A brief description of the manga Bonkotsu Shinpei No Monster Life:
The protagonist is an ordinary soldier from an empire at war who gets used as a guinea pig for genetic engineering experiments, turned into a monster and put into cryosleep.
200 years later he wakes up in a sword and sorcery world. The empire is gone and he has to survive alone in the body of a monster whom everybody wants to kill on sight. Meanwhile he encounters various pretty ladies (and elves) in need of rescue.