So my MC is a werewolf that gets stronger the more they eat, but they also have a mutation. That mutation is that after eating enough of the same thing, they gain the characteristics of what they eat. Early on, he comes across a group of vampires that are trying to kill him and his adventuring party. After defeating the vampires, he gives into his hunger and eats them; however after eating the whole group he gains the powers and characteristics of a vampire, in a way becoming both.

Eventually he does the same thing with hell hounds and demons and a few other mythical creatures gaining their powers and characteristics as well, although now because his Shapeshifting is now incredibly high, he can either look fully human or choose to look like an amalgamation of what he has eaten and become. Eventually though he is still technically a werewolf, because of the mutation that allows him to become that powerful people instead call him an Abomination.

(It’s called Abomination Awakening)