Cole is drowning, killing makes him feel more real (i'd like to think it's because of the dialogue with his victims, he feels more real because someone finally notices him - later he used Rhys for that purpose, thus he didn't need to kill anymore). He is a mage and a rogue. With super power of invisibility (or something). Abused kid who cannot differentiate between right and wrong (kids are cruel because for them legal systems, morality and all that crap doesn't exist). His origin is unknown - he might be a ghost, demon or a spirit. Dreamy eyes, awesome hair. and no... Cole's not whiny. Werther was whiny.
he's a very well designed character. author really put his mind to his creation and it shows.
i dislike Cole, pretty much for the same reasons i dislike Wesley Crusher. for both chars i'd be perma banned from every good tabletop group i know. too overpowered. too cool background. too many awesome things put in one giant pot, in contrast to, i dunno, Evangeline?