Xivilai Solin- Glowing red-fisted, and otherwise darker skinned and larger Xivilai? Flame-enhanced and defense up against flame.
Æther Atronach- Original form is a purple-ish version of flame atronach, but changes into other atronachs during combat(Don't know if that is really a good possibility).
Dimension Walker - Will o wisp, White colour scheme, but will randomly Chameleon a few times during combat.
Colour Scheme for Aerid: Just a smaller, regular coloured, Scamp. Thats burning.
I'll add more in a few minutes.
*Edit 1:
Daerien - Alright, a Dark-purple daedroth, same size, but it can use a "Blink" spell, or something to that effect. Lets say, it spots you across a large hall, it can cover the entire hall in just 2 or 3 blink steps. Or it can just zap right in front of your face. I don't know if thats a really good idea to create, but it's just a thought.
Edit 2: Alright, something simpler with no scripting.
ClannFear Hunter - Faster clannfear, black, with maroonish parts(Maybe glowmapped? Your choice)
Spider Daedroth Queen - Head crest can be Cyan and Gold. Rest of the body can be Dark purple and Forest green.