I like Tyrian because he doesn't have to have a reason for what he does. He's just a Salem worshiping lunatic, and that's honestly a justifiable reason for why he does what he does.
Can't say the same for Cinder, Mercury, Emerald, and Salem though. So far they're just "the bad guys". They have no motive, and they even acknowledge their own "evilness", which is a big no-no when trying to portray a character as an actual character, with their own LEGITIMATE reasons and motives behind what they do.
I can understand Adam's whole thing. It makes a lot of sense. Oppressed and fed up with the lack of change the former peaceful movements tried to bring, the faunus sought a nationalistic identity in a more war focused White Fang that could claim them everything they've been denied up to this point. It's something that our own history books all over the world prove can actually happen when your people are treated like the Faunus are for way too long.
I suppose Salem still has a chance at being humanized a bit. From what I've gathered, humans came after the Grimm. Seems like The Grimm are actually the victims, being slaughtered just for existing. Perhaps the world technically belongs to Salem, and she just wants to revert everything back to the way she intended it for the Grimm. At least, I hope SOMETHING like this comes up. The Grimm just being left at "oh they're inherently bad even though they came first try not to think about it" just screams sloppy writing.