They will both be approximately graceful about being ordered out of the secret archmage conference by the mysterious stranger. "She can't help it, it's her entire personality," Nefreti says to Morgethai as they go.

"I can cast a variation on greater possession where I could possess you, and then return control of your body to you. We would have to test it, but I believe this might allow me to cast a time stop and have it affect you. And you could then attempt to dispel the gate… With a greater maximize rod, I can get you eleven moments across three time stops, which should suffice, I think?"

"But to do this I have to let you possess me."

"Yes."

"...And keep this capability of yours secret from all my allies."

"Yes."

"So there's nothing particularly to compel you to stop."

"...I suppose not."

"Do I have your word that you won't do anything else while you have me possessed?"

"Yes. Would you believe it?"

"Slightly more than if you wouldn't give it."

Well, that's not unreasonable of him.

Manohar isn’t an idiot. There’s discussion of whether maybe Hell will send them an archfiend, at this point, but Hell objectively should not do that; single targets are what the enemy excels at. If you want to take their army down, you don’t want to use something extraordinarily powerful and dangerous that is possible to shoot at; it’ll just get shot at. You want to use something that one cannot answer with firepower. 

He gets permission to sacrifice a couple thousand people to Deskari with shocking ease. Usually when he asks permission to sacrifice a couple thousand people he gets lectured about how his experiments are expensive and he should buy slaves like everyone else does. 

An enormous unholy swarm of bubonic-plague-carrying locusts descends on the army and also on large swathes of Andoran; those who die of the plague have locusts burst out of their body and join the swarm.

Try solving that with a gun.

Guns? No. But the plague was one of the enemies Alfirin and Iomedae were expecting to face on Golarion. Alfirin was not able to memorize all of pharmacology, but Tetracycline synthesis was an obvious choice, to cover the gaps in penicillin's effectiveness. Lastwall's been stockpiling the stuff for the next plague outbreak for almost a year now, and if they don't have enough for a regular widespread outbreak they have enough for the army and to supplement the clerics working in Andoran, and between Abadarans enticed by cold hard cash and Pharasmins ticked off about Tar-Baphon and foreign Good clerics who are... Good... and perfectly willing to go treat plague victims if someone else can arrange transportation, that's a lot more clerics than Manohar was probably expecting.

Also it won't do Andoran any good now but in a year or two if the swarms are still a problem they'll have DDT. She and Iomedae had originally decided learn how to synthesize it to kill all the mosquitos eventually, but she had already decided to accelerate the timeline so it could be used at the Worldwound, mixed with holy water. Because fuck you, Deskari.

Even if you could get their clones (and Alfirin has an idea of how to get their clones), Abrogail Thrune and Aspexia Rugatonn are hard to assassinate. The palace in Egorian is enormous, substantially Forbiddanced, substantially Teleport Trapped, substantially underground. Its staff are mindread and closely monitored. Much of the staff has permanent arcane sight and will notice magic items. People who shouldn’t have any spells up are routinely sent down hallways that dispel them. Both the Most High Priestess and Her Infernal Magistrix go around with guards, and both of them are very powerful in their own right and wearing spectacularly expensive bracers of armor, and no one can get into melee range of them unexpectedly without being murdered.

Cansellarion has four people in the palace in Egorian. They don’t tend to live very long,  sometimes because they get caught and sometimes because the rate of murder of staffers not suspected of treason in the palace in Egorian is fairly high. They report via regular scries, during which they’ll hum lullabies and nod or shake their head in response to message questions. Three of them are people too weak for an alignment reading, in roles without much secure access and with less close surveillance; the fourth is a paladin of Iomedae's with an item that masks his alignement, who is allowed to haul heavy things to secure areas by virtue of being able to pass detect thoughts screening; he has fairly severe brain damage most of the time and is observably too stupid to be planning anything.

He smuggles two guns in, special ones carefully designed to look like a metal measuring tool with moving parts, needed for some construction. The guns aren’t magical; the bullets are, but they are in their lead-lined chamber, and won’t show up as such to anyone looking. When a voice says his mother’s name in his ear, he heals himself with Lay On Hands, and briefly remembers his purpose. 

“We need you to shoot Aspexia Rugatonn. It will probably take two shots. There isn’t an exit plan. The other gun is for Nantes.”

He is not fearless by Iomedae’s power (someone could notice the auras, were he that powerful); he’s just, you know, the kind of person who’d do a job like this in the first place. He smiles broadly. 

It's much easier to soul trap people when they wake, disoriented, in their clones, especially if you have gone ahead and laid some cursed items on the clone three moments ago.

Abrogail Thrune wakes in her clone and re-buffs herself and alerts her guards and takes Aspexia's hand for the Plane Shift to where they'll be regrouping, which is her last mistake.

Felandriel Morgethai considers herself too dignified to do things like shout "why! won't! you ! die! already!" at her enemies but when they learn Razmir sacked Vellumis in a Time Stop again she is very seriously tempted. Instead she and Nefreti, with the magic item from the mysterious third archmage, chase him home, again. He's Mind Blanked but the thing Nefreti's using isn't precisely divination. It is, she says seriously, that it's been done before.

This time the plan is to dump him, beaten unconscious and then Baleful Polymorphed, in Nirvana and if Hell wants to try to retrieve him from there it won't be Golarion's problem.

The moment she's done with Abrogail, Catherine possesses Cansellarion. She casts her spells; a maximized time stop, a wish to bring them inside the forbiddance. A limited wish from her staff to destroy some of the intervening walls, and a second that she casts herself using Alex' blood to power it in place of a diamond to punch the rest of the way through. (He's a paladin. He has blood going spare.) She gives Alex back his hands to make his first attempt before she has to cast another time stop -

It's a little strange, being in a time stop. There's a pit fiend frozen in place almost within arm's reach. He can see two more by the gate… Second Alfirin said he'd have seven or eight moments, and while that should be plenty of time it won't be if he wastes it all staring. He raises Heart's Edge and wills it to unravel the gate. It goes down the first try.

Catherine casts another time stop. Then a second spell, not one that Cansellarion recognizes. And then a plain old teleport out, forbiddance be damned.

There are not a lot of people who could convince Lastwall's leadership that at the moment of his great triumph they should assassinate Alexeara Cansellarion for no reason they need to know about, but Marit is one of them. They'll do it very temporarily, obviously.