Km is an excellent champion, when he has those indestructible charges from his sp2, he can tank sp3 without taking any damage... His crit bleed mechanic is a great counter for The Thing, he gains a 16 second true strike when countering a special, not to mention his excellent synergies with void, st and winter soldier... Definitely r4 material
Yup he is good ,if you got synergy with void and Sabertooth that will be great