Those oni seem ..familiar.

Aaaah, the Blue Obama! Egawd the horror!

Who are the huge face, and face on chest guys?

r1c47 said:
Who are the huge face, and face on chest guys?

Not sure about the huge face, but face on the chest guy is Hanma Yujiro, a character from the martial art manga: 'Baki the Grappler' (the 'Oni' face was actually the shape of his back muscles.)

tarak2002 said:
I think he's Hanma Yujiro, a character from the martial art manga: 'Baki the Grappler' (the 'Oni' face was actually a shape of his back muscles.)

Haha, I was actually about to tag that: hanma_yuujirou

Huge one is called "青鬼"(A-O-Oni).I think Blue Oga is simple translation.
This oga is from free terror game named "青鬼".