@Goldfish sorry for double post, but I wanted to bring stuff to your attention; apologies if there are obvious reasons why not to do these, but:
Waymar does the switching thing with vigor on the move action of his dimension door round, so that saves his move action later for a better thing you come up with or just general flexibility.
Dany uses her bead of karma as a standard action on the same round as waymar is casting dimension door and gets the boost to her divine caster level from 14 to 18. So four more of the weights and the big dude, provided they re in range. And better chance to beat the weights cl if that's a factor
Can Dany alter fortune the amber scarocophagus attempt?
Thinking in actions the NPC's could take, only one good spring to mind:
The two NPC's stand there and
stay within 10 feet of Visery's!
Tbh, I'm glad that you added in the warning, but this stuff read as though it forced awill save to avoid a morale debuff on Viserys, it was that horrifying, and he's a hardened adventurer who has been seeing what red dragon like to get up to for fun since he was 13.
The two NPC's are gonna teleport in and see the children.
At this point I've talked myself into having Varys share a mental impression of the horror and the Command "no matter what you see, what happens, you stay within 10 feet of Viserys"
That thing has at will come of cold, and the buffs one could expect in a place of power, so shit like low level mythic, or quickened SLA or double action in here are not impossiblities.
Like, unlikely to be any of those in particular, but something.
Double cold damage or such.
I don't expect it, but I would not be entirely surprised if it could bypass, partially, our anti-cold shell.
But if it can... It probably is with something that would fuck up the NPCs really bad if we didn't have it.
Edit: Eldrich breach is love