Iomedae's not strong enough to kill a graveknight in one charge, so she doesn't actually try as they barrel at each other. Instead she just tries running the steel bull he rides right through; that'll break the charge, anyway, even if he has a backup Fly like she does.

The bull is undead and shows no fear of her lance, which is unwise of it. It's dead in an instant, and Racher takes off flying, smashing her own horse's head in with his axe before turning to swoop after her. He has a hero to kill.

But this is only the start of the bloodshed. The undead charge might have worked if the Second Army's cavalry had been leaderless, but with their momentum behind them they are incincible. The graveknights and other mighty dead at the head of the undead force can hack their way through the Taldane horse, but the troops they lead will be impaled, ridden down, trampled and otherwise destroyed, the living fleeing and the dead destroyed. A poet will eventually compare it to an autumn tree suddenly struck by a sudden wind, the heaviest leaves falling and the rest scattered by the winds.

She too is in the air and turning back around as her horse goes down, letting the lance dematerialize as it falls out of her hand, drawing her sword which Arazni made deadlier and which she can make holy besides. The impossible clarity and assurance is still about her; she does not believe in her own invincibility, but that the battle is won, that there is only mopping-up left, she believes unshakeably. 

Perhaps Coronesti can kill her. But Taldor will triumph; there are a thousand more of her.

No, there aren't.

A week ago Iomedae fought with the caution of someone who was reasonably sure that her death might mean the destruction of everything she cares about; but now she has solved the puzzle that was set her, now the Church knows the need and has called their aid, and it has not in fact occurred to her yet that she might still have any reasons to protect her life in any case where she would spend someone else's.

They can debate that later, because not unrelatedly she's busy in hand to hand combat with a terrible and powerful graveknight right now.

And she is busy too now, waiting for Tar-Baphon to witness in his scries an aggravating but wholly explainable military defeat, one he has no reason to think he can't reverse quite trivially -

Aroden's greatest weakness is that His slaves are men - weak, petty, disposable, selfish, short-sighted insects who can only manage to walk in a straight line the way real insects do on a particularly good day. 

But also they are unpredictable. He looked patiently ahead into the future, planning this battle, and he saw these men's ruin. Their commander would be slaughtered in the first few seconds, by men he trusted; their officers would betray them; the soldiers terrified and confused would turn and flee, and be hunted, and the Second Army of the Shining Crusade would rise again by nightfall, in vastly improved order, ready to serve in death.

Instead they have done something else. Called a miracle from Pharasma to strengthen their blades, and helpers from Heaven to die in their futile defense, and wizards and priests from the capitol. It is ill news, in that it means Oppara has in its blundering idiocy blundered into taking the threat seriously. And it is ill news in that they did it without his being alerted; the city is woved through with spies, and he really should have heard. 

He is uneasy. But that's all the more reason to slaughter this army very quickly, and then retreat to investigate how the error occurred. 

Time Stop. 

Gate, oriented horizontally and opening out of the ground in the middle of the Taldan infantry, to a demiplane full of hungry grasping horrors that yearn for the flesh of the living. A great many of the soldiers will fall into the Gate instantly when the Time Stop expires. 

Another Gate, somewhere else, to a different demiplane. 

Meteor Swarm has, among ninth circle wizard spells, a poor reputation. You can sink ships with it, but you can also sink ships just by dropping rocks on them from very high up.

That is because most ninth circle wizards can't actually master Meteor Swarm. It is one of those spells that doesn't really hang together properly until you are a bit more than a wizard, and is not employable in its full glory until you are to most approximations a god. 

The real spell cuts four burning blazing lines twelve hundred feet in length, killing everything in those four lines, and then explode at their destination into enormous explosions that bypass all protection against fire - they'd even kill devils, were there any in the Taldan lines - and leave only smoking craters behind.  

Extended Maximized Mythic Time Stop.

A seventh circle priest of Aroden and sixth circle priest of Aroden will find themselves still in motion, on a battlefield that is otherwise utterly silent and still. (And smouldering, from the Meteor Strikes, but a few thousand lives are not the stakes they're playing for, right now and right here.)

Mythic Haste. Mythic Fly.

"Invisibility Purge, and go find him," she instructs them. 

When archmages fight, what usually happens is that they don't fight. Their summons fight, their constructs fight, their minions fight, and they intervene occasionally with a decisive spell and then flee, and it is very nearly impossible to find them. Even if everyone involved has the heightened senses and heightened spellcraft to pinpoint from precisely where a spell was cast, that just implies a rapidly-expanding volume in which the caster could be anywhere presuming they didn't teleport. See Invisibility can do nothing against Mind Blank. Glitterdust is countered by a Lesser Globe of Invulnerability. (So is Invisibility Purge, ordinarily, unless one's god inexplicably handed it out at fourth circle today.) Nex threw around some very large-radius antimagic effects, in the early years of his war with Geb, and everyone knows how that worked out. 

Two mythic hasted flying clerics with an invisibility purge that bypasses a lesser globe of invulnerability are travelling faster than a charging horse, sweeping in each second a volume of five hundred thousand cubic feet, and the volume in which the caster can be found is not increasing, because there's a Time Stop. 

They find him. Frozen in midair, already a thousand feet upwards and northeast of where he fired the Meteor Swarm from, lining up another spell. 

Have a scroll of Mage's Disjunction, each of you. Most clerics of other gods couldn't do anything with it but Aroden offers the Magic domain and any priest with any sense takes it. 

"When the Time Stop expires, read it." Battlemind Link. And she takes off flying, because Disjunction won't work anywhere near her, and she gives them a countdown in dancing lights as the Time Stop ticks down. 

Mage's Disjunction.

He counterspells it. 

Mage's Disjunction. 

He cannot counterspell it twice in the same instant. 

The main reason this hasn't been tried before is because there's no useful followup. There is no power alive on Golarion that can land a spell on Tar-Baphon, is the thing. The most powerful person sworn to the cause of the Crusade is the high priest of Pharasma, and he is a dangerous man indeed, and no spell he casts would touch Tar-Baphon. It's not a matter of luck - it's not 'it won't usually work'. It can't work. 

Arazni is not a mortal, and the laws of mortal magic do not bind her, and she can land a spell on Tar-Baphon, more often than not, if she really needs to, if she is prepared to tell the universe to stop obeying all its ordinary laws and obey her instead. 

Nonetheless this does not usually work. She has played through this fight a thousand times, in the last year, tested every detail of her positioning and her allies, showed her hand sometimes and sometimes concealed it much more closely, and - fifteen percent, that's what she has. Fifteen percent of the time she raises the ruby clutched in her left hand and casts this spell and ends the war. The rest of the time it goes on for decades, and the ultimate result she cannot foresee.

For that fifteen percent they arranged all this; the doomed campaign of the Second Army, and its present peril; the siege of Canorate, the fertile desperation into which Iomedae's clever idea could be conceived and born, the death happening all around her, all to take a shot that likely won't work. 

Trap The Soul.

In some worlds, somewhere, her spell brushes aside Tar-Baphon's near-immunity to magic and gets its claws into his mangled soul, and the magic items he wears that are a contingency for this turn to powder, and aren't sufficient, and his constructs and minions and slaves move to intervene, and are too slow, and she Plane Shifts back to Nirvana, gem in hand, the matter settled.

But not in most worlds, and not in this one. In this world she overcomes his near-immunity to magic, and the spell gets its claws into his soul, but he can change the rules of the universe too, and does, and fate goes white-hot in the place where both their hands are outstretched to tug on it -

Aroden, he realizes at once, and then uses his boots to depart, as they can't be counterspelled, and then stops time and plane shifts to safety and by the time he's finished replacing all his protections he can identify what, specifically, Aroden has done - the coward -

All right, game's up, time to play it. Half a dozen of Tar-Baphon's minions teleported in with him and are scattered around the battlefield; a dozen more were here anyway, to fight. She does another Time Stop and pulls three of them into it with her just so the rest can't interfere.

Plane Shift to a custom demiplane where she'll deal with them in the next two minutes before Tar-Baphon thinks to Wish them out.  Imprisonment, for someone whose spell immunity included Plane Shift. Plane Shift. Plane Shift. Telekinetic rain of Aroden's Magic Army-enhanced daggers, for everything that just needs to die.

A minor tweak to the laws of magic to make all her spells Threnodic for a little while, and then - Mind Fog. Dominate Monster. Dominate Monster. Feeblemind. Feeblemind -

( - the Dominated enemies are set at once to killing their rivals among Tar-Baphon's troops, an order they don't even tend to resist, and then to stripping off their magic items and flinging them towards the enemy and shouting their true name, an order they do tend to resist but not usually with much success -)

And the most powerful undead in Tar-Baphon's army are broken like matchsticks. Tar-Baphon has invented a spell to allow undead to use Clones, but all this means is that she doesn't kill them, she feebleminds and dominates and plane shifts and occasionally petrifies, if she has to. Arazni can see the future, has seen the future, and she kills them one at a time. Sometimes they have the reflexes to Plane Shift out immediately and the most dangerous fall in an instant and the rest flee, sometimes they are a little slow to reach for it and so they are a little slow to fall, some can't escape on their own and those can die last -

- Beneath them, the undead army's morale breaks. Their cavalry is broken, even if its captain may still be fencing with a paladin, and the zombies and skeletons cannot break, but there are plenty of others who can survive and want to. Very few ghouls can Plane Shift; some of them push for the river, for its cover, others simply flee in whatever direction they can. Living wizards cast Mount and two Invisibilities if they have them, or Gaseous Form, or anything else that will let them escape, because anyone with a horse is riding for safety already. A few contingents stick together, because those are always the hardest targets to hit on a battlefield - 

And the Taldane army, seeing this, rallies. Arrows are spent and many of the spearmen have been injured again and again, but now they can press forwards and with them the humble archers of the infantry with dirk and hatchet eager because they've won, they've actually won, against all odds, and now the undead can die by the dozen and any few unspent arrows from those who had benefited from abundant ammunition spells can be spent taking down the wizards who raised the army in the first place -

Urkemkhufu has Plane Shift prepared. Time to leave.

Plane Shift, for another fleeing enemy. Flesh To Stone, for Urkemkhufu.

For someone without biological processes, he's really very good at resisting spells resisted by your body's internal fortitude.

In this particular case, it doesn't help. Urkemkhufu is now a statue in midair, bow still clutched in one rocky hand and quiver over his shoulder.