Great drawing. This one looks tough, but i will still make a fight tactic!
Stealth, otherwise none.
1.If stealth from the back, the wings(gotta be some arteries there!)
2.just below stomach(from a distance suggest max force, iron tip)
3.neck, head(exept forehead)again eyes=ideal target.
Ps.i suggest you design one that has no weaknesses(helmet,eye protection,neck protection).