The Warlock's reality manipulation normally affects laws and rules of the universe, rather than a specific kind of object or medium. I can't really go into specifics, as it can be utilized in many ways, but it's safe to say that anything resembling elemental magic is not likely to be in the Warlock's repertoire. 

Damien Graves is accepted, but needs quite a bit of nerfing. First, he cannot be a lich unless he looks like a lich. He would definitely be undead, so he would look like an undead, decayed or shriveled. The phylactery is almost always a small container with certain elements in it, rather than a solid piece. I like your death knights, but the female will not be able to do any magic besides minor necromancy.

Marianna Delacroix is accepted. I have no real critiques for this character. She is well put together and manages to also be non-stereotypical. I'm impressed. ^_^

Khor Karakas is accepted. His abilities aren't quite how I'd laid them out, but they are similar enough and balanced enough that I have no objections for now.