Innin is so good, but we get limited because we have to stand BEHIND te mob to make it work. Most high level content even forbids us standing behind the mob (or instant death).
Please remove the need to be behind or infront of the mob for Yonnin/Innin to work.
Also the "decaying" strength over time is painful and would be nice if it stays at a constant level (like berserk/agressor) all the time.