Unfortunately I don't know Mattie's (though I've loved to read her threads and her reactions to everything) or Adrian's canons at all (I really do need to check Watchmen out soon). However, Dogma I do know, and in my opinion, you have nothing to worry about in regards to Loki's voice, you're doing great! You strike a really good balance between all the sides of him; the brash, blunt dickhead with serious issues and the kind of easily excited, more laid-back guy who just likes his movies and video games. You also incorporate the uncertainty, for lack of better word, of not having Bartleby around to sort of guide him along - or to hold him back, whichever fits better. What I'm trying to say is that you are mindful of all these different facets to the character and to me, it comes across in his threads in a way that feels very much in character.