Dark Side - New Units/Spells/Skills

[Shadowcran]

What I'd like to see in an expansion:

A way to play the dark elves early on. Perhaps the storyline could revolve around Half elves and their shunning by elven society.

Wyverns as opposite to griffins. Has poison tail usually in fantasy.

Lich as an undead resurrection type unit. Perhaps level 5. Perhaps a way to make them at shelter by converting Necromancers?

Dark Elven Spider Riders, unless there's an issue with D&D and the drow riders.