Krista Yeager - A deadly contractor under employment by Doctor Smith who is hired to track down Gabriel for reasons that begin to unfold, which is related to his mysterious origins. She has a mysterious past of her own and is desperate to find out just what she'll become. Cold, distant, badass. Shoulder-length, brownish-blonde hair, wears green army-esque jacket with sleeves rolled up, then default of top, skinny jeans and boots. Weapon of choice: probably sai. (Reference Pic: Just the face, not the outfit: http://www.comicbookresources.com/prev_img.php?pid=30267&disp=ilib&oty=1&oid=56508
Doctor Smith - A secretive man we see in a few scenes for the first few volumes. He is a surgeon and has a "mob doctor" vibe about him, as we can see him performing surgeries and experiments and the like. It emerges later he has been experimenting with demon and human DNA, which will tie-in with Gabriel. He's creepy, short and something of a sadist. Don't have a physical description yet.
Donna: What happened? Do you want to talk about it? I have ice cream!
Harvey: It's 8.A.M.
Donna: Which is why God made Chunky Monkey. It has chocolate and bananas. Bananas are part of a healthy breakfast. And who cares about bananas? It has chocolate!...Okay, you caught me: I don't even eat the bananas.
--Donna and Harvey, "Suits".