Ok, DEFINETLY getting thos Gantz vibes now.
Also, if you can drop him anywhere, why not drop in an active volcano?
I mean.... I get they can only use it in Japan, but boy howdy, the smartass careful killer hasn't taken THAT into consideration as a way to dispose of big problems?
Let's see.... Boom. Mount Aso Nakadake crater. Effectivelly a big boiling pool of acid. Let's see one of them walk THAT off.
Sure sounds like a great equalizer, doesn't it? Better than hoping physical trauma would do it.
OH, and now the thing is using other people. Guess they did manage to piss it off.