This is Kronix, and he is The Iron Angel. He is a To a of Air (green and grey) and Shadow (black and red). Kroniox was never able to fly like many Air Toa in the past, so he used his mechanical genius to craft himself a set of working detachable wings.
as his Arms are moved, his wings will move with them because of the piston-like attachments on the shoulders. The wings can also easily be stored downwards.
Overall, the design is really nice and the colours are pretty well distributed, but the mask being black looks out of place with the rest of the MOC’s colours.