I've been making it using Skulltag, but I've only been using code from the ZDoom wiki, so it should run OK.
Download it here
Heres a feature rundown (version 0.2.0):
Affrit:
Weapon 1 - Claws (good for taking down isolated foes)
Weapon 2 - Stone Form (Renders you vulnerable, but heals you)
Weapon 3 - Fireballs (optionally with flechette breath. Increases in power as you gain mana. Can be further boosted by discs of repulsion)
Note 1: The affrit cannot wear Bracers or Boots of Speed, and can only carry 1 quartz flask at a time (due to their weight).
Wendigo:
Weapon 1 - Standard wendigo attack
Weapon 2 - Blizzard (A strong freezing gale that not only freezes your enemies but gets them out of your way

Weapon 3 - Comet (An ice boulder that explodes into a brief cloud of freezing gas)
Weapon 4 - Totem (Still experimental. Explodes after a short time, blasting anything nearby to pieces)
Ice Flechettes - Wendigos use flechettes to make a small fountain of ice. Deadly, but short lived.
The weapon sprites are still not done, and there are still some bugs. Also, these classes still need balancing, but its still fun!
If you could help test this, I would much appreciate it.
EDIT: By the way, I'm interested if anyone wants to help, either with bug fixing, or sprite creation.