The Animal Inside

A genetically altered superhuman soldier is transported to Equestria to kill everypony. He is extremely violent and unstable, but he doesn't want to kill. Especially since he has come to love the ponies. However, a mission is a mission. He cannot disobey orders, or he will be exterminated, and they will send another. But what if, instead of being its destroyer, he became Equestria's protector?
Just what if? Also, probable romance!