his double block is annoying, especially when other peoples block 2 attacks a round every round without fail and on a good day yours blocks maybe 1 attack in 5 rounds.

But in terms of unbalanced ninja there are far far far far worse than kimi in this game, and his mystery is the ultimate double edge sword, since it buffs your mystery damage too unless you face a whale with a huge power advantage ( which you would lose to regardless) then it is entirely possible his barrier comes back to bite him in the ass in round 2