No, it doesn't. Critical hits increase the damage DEALT, not damage VALUE. If it's not modifying a combat value, it's not subject to the rule of three.

One shotted him with Dove. Ahhh, the memories!

Well your wish has been granted...Although shuma can be devastating with the mole man combo....he really doesn't need him. There are feats that allow you to mind control friendlies but they must take an unavoidable damage afterwards. Fortunately for shuma he heals a click at the start of his turn thus negating that penalty. Even without friendly mind control he is in his own right an insanely effective piece.

Eye without a face / No OP Kit? A disgrace / WK put him in his place... :(

Can we please get a new Shuma, Wizkids!?!? How much longer do I need to endure my favorite Clix sitting on the shelf, gathering dust??