Ok. The concealment is largely useless in fights. The character is far too conspicuous and loud in both her personality and fighting style. Even with Mu's nullification technique you'd still be able to find and keep up with Rumia if I'm perfectly honest. I don't enjoy exploits on my characters too much.

I was thinking out of battles, she'd play the role of unlikely infiltrator in some places. The ability is actually nifty when you want to play actual ninja. If that's still not great then okay, standing still it is. It's not really big deal, was mostly going for some silly gimmick.