He was nerfed already in the last live update. It would be good if you could provide some more context/feedback on what you believe needs to be changed.
Shinobi is fine, ive been playing as him lately in an effort to be better against him, and i can understand people saying hes annoying, but hes not a threat like a lot of you seem to think, my advice, dont stop throwing out hits, any hit on a shinobi is a big deal for him. He can be killed very very easily.