Preliminary plan. I'm half hoping this is all some sort of illusion or a test arranged by the Shaitan. Good thing Viserys never used his earring in the previous encounter, as True Seeing will help us figure that out.
[X] We will aid the Shaitan, as we are not in friendly territory and we have no way of knowing who tracks our progress through Divination magics.
-[X] While traveling toward the cavern at best possible speed, Viserys assumes MHD form and casts Shield and Mirror Image. Right before entering the cavern he uses his earring to gain True Seeing as a Swift Action, then casts Haste, Greater Blink (using two 4th level spell slots), and Freezing Glance.
--[X] Viserys opens battle with a Searing Agonizing Firebrand, targeting any Forgefiend he can see, carefully avoiding any surviving Shaitan, and the corpses of the fallen if possible, then uses Freezing Glance against the nearest enemy. He follows this with a Necrotic Bomb, again avoiding Shaitain, then casts Celerity, targets another Forgefiend with Freezing Glance, and uses Imperious Glare against any survivors.
--[X] Dany casts Streamers, sending both Streamers against the Forgefiend she believes poses the most danger to the beleaguered Shaitan.
--[X] Richard uses his amulet to gain 12 Temp HP as a Swift Action before entering the cavern. Once battle begins, he chooses a promising Forgefiend to engage, using Shock Trooper to Pounce on it, then Power Attacking as he sees fit.
--[X] Malarys casts as he sees fit, hopefully either targeting a single Forgefiend for destruction or attempting to impede all of them.
--[X] Echo Caller does as he sees fit.