Lady Eriape Speaking. Sixth circle wizard lich escaping Cheliax. Requesting access under Treaty. Intend to Help. Request instructions for peaceful approach. Scryable reply preferred.

Having your fort under Mage's Sanctum, means that people can't Scry you. For hostile wizards this is good. For friendly wizards this isn't so good- they can't scry, so they can't make contact. Sensible wizards will then make contact with patrols instead.
Non-sensible wizards do non-sensible things, as usual.
This one did a [Mage's Decree].

However:

• She did it rather than just showing up.
• She didn't send it to anyone who was asleep.
• She didn't send it to everyone, just the command structure.

So one could possibly work with this person. Fortunately, Hans Terzić does not have to deal with this.

Maëlys got the [Mage's Decree] as well.

She sighed, knowing that this was going to lead to more trouble for her. She was right, of course. She's always right. Some time later she found herself ordering Jac Shad, a song-sorcerer on punitive detail, to go outside, wearing a sign with instructions on how a lich should safely approach adventurer's fort. 

Jac doesn't get the [Mage's Decree]. He also chooses not to wear a hat when going outside. 

"Hello Mister Man. May I read your Blackboard Please?"

"AHHHHH!"

Fortunately, he leaves the blackboard. Clarabella reads it, and burrows away into the snow. She likes the snow. It's soft.

Seventeen days later, Eriape has proven that she actually can, and will Flesh-to-Stone major demons. 

Forty-three days later, Eriape has died six times, and has shown how useful it is to have a wizard without regard for her own safety.  

Everyone's still waiting for this to go terribly wrong. 

Crusader's fort is not usually a particularly favored target of the Abyss when it comes to breaching the worldwound lines. The allure of the vulnerable mortals on the other side is still enough to prompt regular attempts, sure, and just like everywhere else on the border it is a victim of attacks due to the constant outwards pressure caused by demon immigration at the wound, but for those demons that are actively picking their targets there's not much to make it stand out. They still get half a dozen incidents on a slow day, but most of them wouldn't pose any difficulty even without a 6th circle lich running support. 

It's not actually that surprising that all the attacks on it in the last month and a half have been readily repulsed, and absent a greater demon's personal attention on the front there's nobody who would even notice a difference. Nothing of note changes about the Abyssal strategy.

Well. Nobody involved in the war effort, at least.

Areelu Vorlesh does not, generally speaking, have the time or inclination to spy on worldwound forts. There are far too many of them, for one thing, and almost all of them are tediously dull. It's not like it's a good way to keep abreast of the strategic situation either; both Lastwall and Cheliax know enough about information security to hold all their important conversations in private sanctums hundreds of miles away from the wound where spying on them would be moderately inconvenient, and any information she could possibly want on Mendev could be obtained far more easily by any of the dozens of abyssal spy networks whose reports she steals. Crusader's Fort is an exception.

Though the rank and file of the fort are much the same Iomedaeans as everywhere else in Gundrun, the fortress is home to a revolving door of foreign adventurers and acts as a central planning hub for any independant operations in the wound. If a group of adventurers are planning a raid on some Glabrezu, odds are they stop by the crusader's fort to organize the effort. If gunners from Alkenstar want to test their newest firearms against demonic toughness, they show up to the crusader's fort to do it. And if any powerful spellcasters want to do their alignment a favor or obtain respite from their enemies, they show up at crusader's fort to do it. It's still usually little more than an interesting diversion, but she's not so busy it's not worth an occasional check, and if they're on the ball enough that a Greater Scrying sensor will get noticed before it sees anything interesting? Well, her Insect Spies are much harder to spot, and aren't totally stopped by a Private Sanctum either.

Crusader's Fort isn't that different than it was, three months ago.

There's a giant snow sculpture, some way outside the walls.

The largest wizard lab is arranged differently

There's twelve undead badgers in a circle singing a working song, as they make [Knight's Banners]. These are quite sophisticated- they protect against fear, and if you have the knack, you can make them to a lot more things, like make you better at fighting, faster etc. To everyone who can see them in battle.

Her insect spies don't have any magical senses, even when she's looking through their eyes, but that's a problem for lesser mages. Her spies' vision is far keener than any ordinary insect's, and needing detect magic to figure out what a magic item does when you can see it being constructed is nothing less than incompetance. That doesn't mean that what she sees isn't surprising, though. Lastwall banners require a paladin's assistance to make function properly, and while there are obviously paladins at the Crusader's fort she really wouldn't have expected them to be cooperating with undead badgers of all things on making magic items. Her fingers itch to read their minds and figure out what their deal is, but using detect thoughts through a scrying sensor requires a specialized magic item to work and hers isn't threnodic. 

Spying on the wizard's lab is a bit more of a risk, but she's still got 6 hours on the duration of these insects and she's actually curious now. What's the deal there? She'll send one to get a closer look at the snow sculpture too, and then target it with a scry to check for anything unusual about it.

Not very well hidden underneath the snow is stone, the twisting marble-granite mix you get with [Flesh to Stone] It's a very large demon, turned to stone and then decapitated. 

Eriape is in her New Lab with her New Friend Maëlys. They gave her a Long List of Rules, written down in careful precision on all four walls, and have added to them regularly as Eriape has come out with new proposals.  

"So if we Turn the Demons, using [Baleful Polymorph] into Pigs or Somesuch, we could then feed them to the Mortals, saving Fortress Resources!"

Why is this her job now? "Because they are or were sapient, that is, in fact, cannibalism. Another for the wall, I think."

Well. Flesh to Stone implies 6th circle, but so does being a lich. Supposedly a merely 5th circle caster can occasionally manage it, but the lethality of attempts is enough it's rare anyone desperate for immortality would try. The badgers are probably hers, then, too; it's a simpler explanation than multiple unrelated undead wizards showing up at the crusader's fort at the same time. Can she see any of the items or spell diagrams in progress, or was she careful enough to hide them all away in lead lined boxes or the ethereal rather than rely on a private sanctum? If not, she'll divert three of the insects back to keep an eye on the badgers and get a sense for how directly the lich is puppeting them. If you can crack bilocation via badgers Areelu will actually be impressed.

Eriape has half a spell diagram here of Arcane Awaken. It's up on a blackboard, she's been trying to teach it to the Senior Lastwall Wizard. The man's also Chelish, interestingly enough. 

She'd have to see or reconstruct the other half to be completely sure, but the mathematics certainly seems sound to slot it into an only moderately unusual wizardry scaffold.  It's probably not worth the time to reconstruct the rest of the diagram and port it over to her own system any time soon, especially when she can already cast awaken with limited wish, but that's no call not to copy it down. Though it doesn't explain the badgers - no, you awaken them and then make them juju zombies, obviously. Badgers specifically because they dig, and wherever she operated out of before that was more useful than flight or opposable thumbs?

Some of the insight in this spellwork is useful, actually. It's mostly duplicated effort with what she has, but not quite all of it, and any master necromancer that can also do this probably has some things they aren't offering to exchange with Lastwall. If kidnapping liches of unknown capabilities out of crusader fortresses without tipping her hand about who was behind it  wasn't essentially impossible, she'd be tempted to go for it. 

...Apparently her phylactery is also inconveniently located; Areelu would rather have less interference from Axis, not more. Call that plan B, then, and kidnapping plan C.