Zennosuke  

Zenmai Zamurai

Zenmai is a shining example of good in his village, but the wind key in his head is big weakness. If he is struck by lightning, the polarity of goodness inverts and he becomes the evil Akutare Zamurai. Under this persona, he plays pranks on and makes life difficult for everyone. The dumplings on his Dango-ken also change to slimy balls which turn others evil when eaten. (Wikipedia)