I'm not sure, but I think the person above Insane B★RS is Noel Vermillion, and the person at the very top is Konoe A. Mercury/Nine from BlazBlue.

is there a theme going on here?

One of drawfags drew this for a waifu drawing request thread.

mirai nikki and yume nikki in the same pic. Win.

*"my waifu" image*
*notices Layton*
Oh come ON!

Since Asagi's game was cancelled, should I just put (Nippon Ichi) next to her name or something?

Two (three after the edit) calls I think; Pink hair in the upper-right-middle is Birdy; post #1373330 and I think fox-ears sketch on the extreme right-middle is Caster-Extra/CCC. I thought the person below-left of Enja might be Black Rose from .hack, or one of her several clones from the other stories, but the facial tattoos don't match.

Directly above professor Layton looks like Asuka. Makes sense since in a waifu pic Rei is there.