Verified answer

alchemy there is no chance you would die from over using it. like the first ep of FMAB showed you could kill people from a few feet away by boiling their blood. with a philosophers you could do almost anything ninjutsu needs you to know all the hand signs and words and if you are not careful it will kill you

Naruto Uzamaki, because he has the fox and can never die :P

I'll have to go with jutsu.

alchemy..