chromatic doom, help needed Options

[Kerkes]

I need some help with chromatc demon. My party is: riskbreaker lvl 21 - long sw +3 and equlizer
valygar lvl 19 - +3 club and +4 shortswrd
ber-cler 9-21 - foa+3, flail+3
ber-mag 9 -18 staff+3
imoen 19
cernd 17
I usually did this with more fighters and the fight was easy. But now I have only two, since my cleric must heal. Imoen seems not to be able to hurt him with adhws after firing 3xlower resistance trigger (she has vecna). Cernd, on the other hand, does wonders with his aura clensing and unleash energy. Isn't that the same kind of damage(magic)? why doesn't adhw work? I don't get any message about what's happening. Yet unleash energy does not seem to be enough (does 20-25dmg) , demon gets "near death" but that's as far as he'll get. As soon as Cernd is out of unleash (he has 6 or 7 I believe), I may as well reload. I've also tried magic missile under imp.alcatry (does nothing) , waiting for demon to switch to ice form so that flame arrows hurt him, but he killed my spellcasters before that etc. Any hints? In his red demon form, how can I hurt him with elements? I just hope it's not ice. I also don't get any message for bolt of glory.

[LZJ]

Unfortunately, you're right. The fire aspect takes the most damage from ice (I believe it's about 50%). Magic damage is generally not very effective and I won't bother with that. His fire aspect is the most problematic due to the lack of ice damage you can infllict.

I guess that you would have to be patient and wait for him to change into another aspect other than fire, since you would not be able to get Rimed Club nor The Truth before beating him. An alternative would be to wait to get Ice Star in ToB, but it's not necessary. Honestly, I personally lament the lack of ice-damage spells: you could try Cone of Cold or Ice Storm though.

SPOILER!

In his Ice form, you could just cast Fire Arrows, as you've noted. Further, your ber-cler can cast Implosion which should help quite a bit (the fire damage should do about 20+ damage plus hold him for a few rounds).

In his Air form, use Treefolk Arm and cast Chromatic Orb/Melf's Acid Arrow.

In his Acid form, use Lightning/Chain Lightning spells + Crom Faeyr. Frankly, I'm surprised that none of your characters are wielding it.