Someone else is going to have to fill in exactly what else is going on. Caster and Saber are obvious enough, but the "credits" up top also mention Archerko, Berserker (is thats upposed to be him in the back?) Hacchan (?) and two I can't read and don't recognize.

The pink haired girl is shirouko from Heaven's Failure. I don't recognise the others.

You sure that's not True Assassin in the background?

darkdaken said:
You sure that's not True Assassin in the background?

True Assassin doesn't have a real face.

I added notes where I could, but the kanji are too small for me to distinguish.

It's no wonder Japanese students ruin their eyes trying to read kanji in small print in those on-the-go studybooks.

Guy in the back is Archer (with bloomers on his head?).

Translating note says:

Underwear soldier (発作的突然変異)

oh wut ? ồ_ố