She is thrown back by the explosion and is seriously hurt, but it’s far better than dying!  Praise the Inheritor!  This is why demon lords are normally sensible enough not to enter the material plane in person!

She doesn’t have that many sixth circle slots to spare but she needs to be fully recovered quickly.  Heal

It is perhaps lucky for all involved that Tanya does not know her intervention is causing the locals to praise god.

Fire effective, target retreating. A bigger shot would take it out but would take too long to charge up and cause even more collateral damage. However, the target's barrier or its equivalent should now be down - she can't make sense of these signatures but if most of her shot hadn't been absorbed by some kind of shields, the result would have been much more impressive - so she can use enchanted rounds and land them on-target.

The advantage of enchanted rounds, besides their versatility, is that they can be fired as quickly as the gun cycles; the bullets and the orbs are both optimized to apply the standard enchantments very quickly. The standard-issue service firearm for aerial mages is a semi-automatic rifle; ace mages can enchant bullets as quickly as they can pull the trigger, that is, several times per second.

Tanya's preferred weapon is a SIG MKMS light submachine gun. It can fire fourteen rounds per second if you fully depress the trigger.

She snaps off a couple of AP rounds followed by a small explosive shot straight into the wound hole in the target, all in two-tenths of a second, to judge the effect.

His raw divine profane nature manages to deflect one of the armor piercing bullets, but another penetrates deeply, even with Deskari's sheer durability.  Its velocity remains even as Deskari's spell resistance negates its active enchantments.  The armor piercing round isn't Cold Iron or Good or innately Mythic, but it has enough kinetic energy to sting even so.  The explosive shot also connects, but it relies on magic activating after contact, and this magic is snuffed out, leaving an anemic explosion that doesn't even scratch Deskari.  Deskari would avoid flinching, but he wants to avoid letting his injured portions be damaged further, so a keen observer will be able to notice him shifting his body to protect the gaping wound in his chest and ready himself to try to dodge further projectiles.

Two tenths of a second is short enough that he's still not through the Gate yet.  He can mentally direct some swarms at where he thinks the latest attacks (extremely expensively enchanted sling bullets, slung at the rate of a hasted veteran adventurer?) came from.  A sling is an odd choice of weapon for a conventional spellcaster, perhaps she is some sling analog to a sword magus?  She better hope she can sling down swarms, haha!

It is deeply unfair that the locals can negate her magic while she can't make head nor tails of what's going on! At this rate the target will escape into the ?magical hole? and Tanya will be blamed for killing bystanders! She needs that thing to stay here and stand trial for - destroying that fortress, there must have been people inside, that is definitely a hostile and a legitimate target, but her bullets didn't do enough damage and the optical spell did but it wasn't quick enough -

Its ?head? is pretty large but its legs are very thin, can she cut through them with optical spells?

She can cut off two legs before it gets through the “hole”!  The demonic construct is somehow relatively unimpaired by the loss of legs.  (Probably some type of magical flight?)  The “hole” is still open if she want to dive and give chase?

She may not have noticed them earlier, but apparently locusts started swarming with the demon attack?  The earlier explosion killed and scattered a lot of them in the plaza itself, but locust swarms further from the blast survived and are gathering again.  Some are flying up in the air (towards Tanya’s location… a few seconds ago).  Some are going towards the legs.

He can continue to direct and sense through his swarms even through the Gate, so he will risk leaving it open another few rounds.  He will have his locusts consume his lost limbs so they can’t be used as spell foci or components against him.

The follow-up attacks are confusing, why would Iomedae bother on a merely annoying and humiliating follow-up?  She’s far too miserly and conservative with her limited power to do that… perhaps he assumed wrongly and the intervention was actually Calistria or some Chaotic God?

Actually… he’s already regenerating from the first devastating blow, which is evidence against a direct divine smiting, which would cripple his regeneration.  Perhaps a less divine intervention, overcharging the first attack, the follow-ups of which took his legs?

He can dig the bullet out of himself to study later.

Why are Deskari’s swarms converging on his legs?  …To stop her from obtaining the legs by eating them!  She’ll blast the swarms with a cone of cold.  

She still has several confusions (why the incomplete follow up on smiting Deskari, how did the demons overcome the Wardstone, …how could she have let this happen?).  But she’ll focus on the fight right in front of her for the moment.

She doesn't understand what Terendelev's construct is doing or why but presumably she knows best and Tanya shouldn't interfere. The insects aren't a concern on her current trajectory, she's climbing much faster than they are and still accelerating. It's a clear day and she can snipe everyone just fine from a mile up.

She could chase the target, it's obviously a loss to let it get away, but that's not a serious option. She doesn't understand the magical hole (?) and doesn't know what's waiting on the other side and isn't about to abandon the safety of the skies to blindly chase down scalps into melee range of an enormous magical construct. Terendelev can deal with it.

...she'll stay where she can see the hole, though, and snipe through it if she gets the chance.

What else is going on around here that she should do something about, were there more terrorist attacks in the rest of the city, is her airspace still empty, visual double-check to back up the radar and magic sensors...

In the city below, combat rages… aside from occasional bits of fire and lightening and ice and glowing weapons (almost all of which are discernible as magic to Tanya’s senses) the combat is clearly low tech: swords and spears and glaives and crossbow bolts.  The demons seem to have more magic than the humans (and human like species).  There is no one seriously approaching her altitude; demons and an occasional human fly, but at speeds comparable to birds (at most) and usually only to gain minor tactical advantages in ground engagements.

Down in the plaza she flew up from, Terendelev’s construct has grabbed both of the demonic construct’s legs, and it is yelling instructions to survivors (although Tanya can’t hear them from her altitude).  A child (or maybe short human-like species) grabs a fragment of the construct’s legs and runs off with it.  The ‘hole’ the demonic construct disappeared into disappears, although there is a more mundane rift left that reaches into caves below the city.

Some demon (one that looks quite classical to earth mythology if Tanya manages to spot it: a small bipedal goat like creature) must have noticed her lower altitude decoy illusion, and manages to land a fireball on it.  The explosion of the fireball is a bit odd if you’re used to more physics-bound explosions, spreading from a point but cutting off sharply at 20 feet.

That explosive spell looks very useful! Her explosions are mostly too risky to use in a dogfight.

Pity she can't make the decoy look like she was taken out, it's intangible and can't smell of smoke and charred meat. She makes it look like its barrier blocked the fire.

As there don't seem to be any real threats, she'll fly down to hear what Terendelev's construct is saying (seriously, is she inside it or isn't she?) - not that she has to follow her instructions, but she'd really like to know whether she can still court her as a local patron or, alternatively, should leave until the situation calms down.

She could shoot all the other ground-bound targets but she'd like to be clearer on targeting parameters because right now she can only strictly promise 'anything that definitely doesn't look human, and also it turns out I can't see through local illusions'.

Terendelev is shouting orders.  "Everyone with injuries form up for a channel.  I want to take an initial group of our strongest fighters down to where the Wardstone fell within the next minute and anyone above a Cure Critical* ready to follow soon after!  Remember if you see anyone acting strangely, Prelate Hulrun and I will have Magic Circles Against Evil up soon!  Those of you able to fight but not above a Cure Critical* I want guarding civilians here, I will decide on where to direct you soon."

Her head turns to a runner to reply to some messenger more quietly than Tanya can hear.  "Have you figured out where the Prelate is yet?"

When Tanya is close enough, under 20 yards or so from Terendelev, her head snaps up as if she suddenly became aware of Tanya.  Her eyes narrow, then widen.

"Tanya?  Is that you?  Identify yourself!"

Terendelev lost track of Tanya in those first few confusing moments as the attack began, but she thinks Tanya flew away, and she recalls Tanya mentioning that she can do illusions as well as flight.

* A slang shorthand for adventurers of enough experience that a Cure Critical Wounds isn't enough to fully heal them from near death.  (With the common understanding that Wizards tend not to be as relatively tough but have magic to make up for it.)

Terendelev is clearly accustomed to command, taking control of chaotic situations and organizing emergency response, and she's used to being obeyed. The reference to civilians implies she's military and that's not the impression Tanya got earlier but if true it'll make things much easier in the immediate term.

(She expects anyone not critically wounded to guard civilians? What a touching dedication to her work duty and the citizens' welfare! Tanya applauds! But she'd rather not work for such a demanding boss.)

...Terendelev is absolutely right; whether or not she can see through the illusion making Tanya look like a piece of sky or sense her magic, not everyone else here can and they're not used to her signature anyway. Tanya is too used to working with her own men; to coordinate with foreign forces she needs to be much more explicit. She drops all the illusions she had running.

"It's me. I could keep shooting at targets of opportunity but I'm afraid of mistaking friend for foe."

That is a cautious attitude, but recalling Tanya’s background it is reasonable, she wouldn’t be able to differentiate tieflings from more humanoid demons.  (…even many Mendevians often confuse them but it is not as if they are actually trying to distinguish them.)

“If you can fly, your aid in securing the Wardstone would be greatly appreciated.  I will assign someone to call out friend and foe for you if you come with us.”

What else is most urgent to communicate quickly.

”Babaus appear emaciated (nearly skeletal), tend to be red in color, have slimy acidic skin, favor the use of spears in combat, and relevantly to you, can see invisibility.”

Did she already mention Babaus to Tanya?  She kind of defaulted to her ‘basic facts for foreign adventurers’ without thinking about how helpful it is.  What else does she need to know from Tanya, or Tanya need to know from her.

“The Wardstone normally inhibits demonic teleportation and cripples them if them come near it, obviously it isn’t working, and figuring out why is our top priority, even above securing the rest of the city.”

She mentally reviews the conversation.

“You said ‘keep shooting’?  Was the follow-up to the divine smiting you?”  Her voice shows some disbelief.

Actually, was Tanya the vector for a divine intervention?  (The attacks that took Deskari’s legs were like a more moderate version of the attacks that nearly slew him, perhaps it was a divinely empowered version?  Tanya didn’t actually get to explaining her planet’s deities.)

"I might be able to assist. Where are we flying?" Terendelev ('s construct (?)) has wings, are there more aerial flight-capable mages here? ...do they have airplanes?

"...I don't understand or don't have context on 'teleportation' or, uh, 'divine smiting'." Was that a metaphor serving as a compliment for her attack, or - are the locals often empowered by 'gods' and that's what Terendelev thinks she did, she had to tolerate that back home but she has no reason to keep doing it in a new world - "I did not pray or invoke any god or receive powers from such," she says firmly.

“The Wardstone fell into the chasm opened by Deskari’s scythe into the caves beneath the city.  If Deskari planned for this, we could be facing substantial opposition already, possibly an ambush.  But he was injured and fleeing so it’s likely this was an improvisation on his part so we will ‘only’ face hordes of demons converging on the location in the near future.  …which is why I want to establish a defense now.”

“Teleportation is instant transport across long distances.  It’s 5th circle for proper distance, 4th for tactical ranges, many demons can do so basically at will.”

She’ll focus on the more believable part now.

“If you in fact did cut off Deskari’s legs with whatever explosion or fire or searing light spell that was… you are a substantially important combatant, probably the strongest offense we have.  Even if you only have a few more it can be invaluable in slaying stronger demons.  I will cast a Magic Circle Against Evil on you and assign people to help protect and heal you.”

Terendelev is practiced at getting foreign adventurers to usefully contribute!

“Even if all you have is flying and you aren’t willing to risk yourself, just helping carry a few people down would help… we don’t have a lot of capacity for that.”

“I have a Feather Fall prepared today!”  A man with a glowing sword interjects with some bravado.

"Instant transportation at will?! At what range, is it line of sight, how long does it take to set up, can you detect it ahead of time or block it, can they fly or is high altitude safe -"

Tanya in any case wouldn't volunteer for an underground (!) assault on a possibly fortified position with zero intelligence but this is much worse than that! Even a mediocre mage could take her out if they got the drop on her! She'd fly away from the city this instant but intelligence can be vital.

All this exchanging information is taking valuable time but is necessary - she’s being an idiot.  She casts a Message.  (The verbal and somatic components noticeably sync up to the mana signature Tanya can sense, and in fact are more noticeable on a dragon).

“Sorry for not remembering to use this spell sooner.  It’s not secure enough for information that needs to be truly secret but at least will avoid revealing too much publicly, it’s about as hard to overhear as a whisper.  To answer your question, the 5th circle Teleport has a range of hundreds of miles but requires a clear detailed memory of your destination, the 4th circle dimension door has a range of over 700 feet and can be done blindly, but at substantial risk of injury.  The Wardstone network normally prevents demonic teleportation across it… but something is wrong with the Wardstone in this city, and if that causes problems for the network as a whole… the entire continent would be at risk to demons if the Wardstones outright fail somehow.  If you are willing to fly above the crack in the earth where the Wardstone fell and pick off demons from a distance- for however long your flight lasts with whatever spells you have left to spare, that alone will be quite valuable.  Some demons can fly but from what little I’ve seen clearly I think your flight is much faster.  I don’t have a lot of liquid monetary funds, but I have 7th circle casting and I will commit to paying what the Abadarans would evaluate as a fair price for your aid in this, up to the value of a quarter of my spells* for a year.  I can have someone on the ground also using this spell confirm targets for you.”

She’s taken Tanya’s focus as deliberately avoiding the question of providing aid.  Hopefully something in that speech will win over Tanya, whether altruistic concern for the world or selfish concern for the world or simple financial interest.  It’s potentially a lot of money Terendelev will owe but it would be worth it.

“I would like to know your decision in the next half minute.  This spell will allow you to reply by whisper as long as you stay within two hundred feet or so.”

And then she’s back to shouting orders and organizing people.

* technically her biggest potential income source isn't a spell but rather a spell like ability to Control Weather, which she has developed just in the past century and still isn't quite inexhaustible in using.

Very short range whisper spell? Doesn't sound very useful in combat, more like something people who spend a lot of time in meetings would want. (This makes Tania favorably inclined to Terendelev!)

She's offering to fairly pay for Tanya's services, so she definitely deserves a hearing. ...wait, weren't the 'Abadarans' a church?

Tanya doesn't want to actually put her life at risk, and with this many unknowns she'd be doing that. But if she trusts Terendelev's information...

Luckily, Tanya has more than thirty subjective seconds to consider her response. She can't keep up the mental speed-up for too long but it's been less than two minutes.

"I will provide air cover if you are sure enemies can't teleport to me and stab or shoot me before I can react." (Hopefully she's whispering correctly? Well, she doesn't think she's giving out any secrets on her end.) "That means the long-range teleport can't target me and the short-range can't be chained, or however that works. Of course I will stay illusioned too. I will still need a spotter to identify targets, unless you're willing to take responsibility for me doing my best using your descriptions. ...or if you want me to shoot anyone in an area whom you didn't preapprove, or can patch me into your secure comms."

"I can't guarantee that enemies won't be able to reach you at all.  We don't have ongoing communication spells, the spell I'm currently using is the best lower circle option for short range constant communication, Telepathic Bond is better but it's 5th circle and I don't have it, I'd be using a reserve scroll, but that is plausibly worth it if you have enough magic left-"

Even if the spell that cut off Deskari's legs was Tanya's, as Terendelev is guessing, it is plausible she's used up her higher circle spell slots (or whatever the analog is in Tanya's magic), so Terendelev doesn't want to use a bunch of scrolls on Tanya if her lower circle spells are less impactful.

"If you have secure long range communication magic, that would be valuable.  I keep running into confusions about your magic and I suspect you are capable of valuable contributions, whatever the limitations on your magic, but I want to seize the initiative on the Wardstone.  We should talk again soon.  If you come back within a 200 foot range of me, this spell will continue to work, for the next hour and a half.  You can also ask-"

Not Hulrun, the man has his strengths but a complicated sensitive conversation with a foreign and powerful spellcaster is not one of them.

"-Irabeth Tirabade is a half orc, that means green skin and teeth like small tusks on her lower jaw.  Her armor is golden color and has emblems of swords.  She leads the Eagle Watch and I think would be capable of figuring out where you can best contribute based on your abilities and the compensation you would ask."

"Any creature attacking people with horns and bites and claws is almost certainly a demon and an acceptable target and in the very unlikely event this is somehow not the case I will personally take responsibility."

In the plaza injured people have gathered within a 30 foot radius of a man who has some type of... heavily stylized computation orb?  Except the mana signature is wrong and he's brandishing it and doing some type of magic.  It doesn't feel like a proper spell to Tanya's senses, but it heals all the people within 30 feet in an instant.

Terendelev grabs two people in her front claws, another two crawl onto her back and she dives down the chasm that was opened up earlier.  The man with the glowing sword makes a running jump in time with another man at his side and they fall straight down into the chasm, but if Tanya is paying attention she can sense him cast a spell just before he lands.

If Tanya pays enough attention, she can pick up a very odd mana signature a ways down the chasm.

"I don't have secure long range communication magic," not to people who don't have a compatible orb or radio set. 

...and she's gone. Well, Tanya made a good first impression, Terendelev is definitely interested in funding or backing her, now she should sit back and let the locals sort out whatever is going on.

Instantaneous (??) area (??!) healing is a tremendous asset! If anyone not dead can be back fighting a few seconds later - aerial combat might be the least affected, most hits that penetrate barriers are kills or at least knockouts, but think of the effect on infantry! 

...or industry, research, dangerous occupations, ambulances and first responders... Tanya needs to stop thinking of the applications to war first. How about the applications to Tanya. Having instantaneous healing spell would be very much worth carrying another orb. ...she shouldn't get ahead of herself, though, it probably takes a long time and high aptitude to master or many more local mages would be carrying one.

Anyway she puts her decoys back and shoots up into the sky. Finding a single woman based on a vague description in an unfamiliar, chaotic city sounds impossible so she might as well take her time. As long as she's in the area, what can she see down the chasm Terendelev went into?

...actually. Wait a minute. Tanya is still processing the full implications of a spell of long range teleportation - not the ones to her personal safety or battlefield tactics but the implications for the world at large.

Civilization is created by people working together, organized into cities and states. 

States are defined above all by having borders, an inside and an outside, us and them. Armies, governments, roads, laws, some states have lost these for a time and recovered. But a state without borders is like a cell without a membrane: incapable of any organized action, undifferentiated from the chaotic soup, an oxymoron.

At war, borders are fortified against enemy armies; in peacetime, they filter and track foreigners coming in; they regulate trade and enforce taxes; they set apart the collective property of nations, just as real and important as the private property of citizens. The very idea of law is a mockery unless you can say: it applies here and not there; to these people, but not to them; here I will do as I will, there I will let you be.

You can't have borders if anyone can teleport past them for hundreds of kilometers at a go. You can't have armies defending land if the enemy can simply skip over them and appear in their rear! Even if only mages can do it, even if they can't take others with them, nowhere is safe, the very concept of safety may lose its meaning.

This city had an aptly-named 'wardstone' which made the teleportation spells not work, and when it broke the local authorities treated it as an existential emergency because it is. No city in this world can exist without blocking teleportation. It doesn't matter who these particular 'demon' terrorists are or whether the attackers here and now are a genuine threat; if word spreads that the wards of Kenabres have failed, every opportunist in the world will come in and they can all be here in hours if not minutes, the chaotic wastelands outside invading this small fortified island of civilization.

(Are there country-sized wards? Borders warded along their length - no, they would have to ward half a sphere - )

She wants to help these people. Not only because if they fail she'd have to traverse the wilds to find another fortified city and gain entrance to its safety. Because they're fighting to preserve civilization and that is a rational common interest Tanya has with them, for there to be more islands of safety and enlightenment and paying people for their labor in the world.

The chasm opens into a cave system which is… odd, to anyone remotely informed about mundane Earth cave ecology.  The most noticeable oddity is that the cave seems to have flora with many different strange plants, some of them even glowing, all without any sign of the cave having had a light source (prior to the chasm that is).  If Tanya is especially paying attention to details, she can pick up signs of unusual fauna as well: giant spider webs, the occasional animal tracks, leftover bones of animals, and leftover carapaces of insects far too large to breathe (according to conventional biology as understood by Earth).

Further down in the caves, at an angle Tanya can’t quite see visually, Terendelev’s mana signature is close to reaching a large mana signature (or maybe it’s multiple signatures, tightly packed on top of each other).  Actually, if Tanya focuses, she can tell it is definitely multiple mana signatures (too many to tell exactly) in synchrony.  The local magic is too different from what she’s used to for her to be sure, but it seems like some of the signatures have fallen out of sync and some signatures are outright disrupting the others.  

Terendelev has reached the multi-signature and has stopped.  Within another minute she is casting a few spells.

If Terendelev isn't in within line of sight then there's nothing more Tanya can do to help her. ...well, she could loiter and see if she or any of her men come running back out or are attacked from behind, and she'll keep glancing at the entrance while she can, but for now she wants to study the rest of the city.

(She has absolutely no expectations about the ecology of underground caves on the alien planet of an interstellar multi-species civilization! Maybe the multiple magic signatures teleported in and installed the glowing flora to decorate the place!)

How big is this city and what is outside its walls? How much fighting is visible, where is it concentrated, what do the combatants look like and what weapons do they use, can she see any spell-effects and start tying them to their magical signatures? Can she make any tactical sense of it or is all her hard-won knowledge entirely obsoleted by tactical teleportation? Is anyone using horns, teeth and claws? Are there many people answering the description of 'green woman with tusks in golden armor with sword heraldry'? (Are there still no other fliers?) 

She'll climb a mile up at least, dismiss her decoys (they'll only draw attention) while keeping herself illusioned in the colors of the sky, and take a good long couple of minutes to evaluate the situation.