Blood Feast: I Swallow Strength, I Shatter Foes

Mark Lowe fights off the invading races that have come for the human world, and he grows stronger by devouring. The bloodline he woke is that of the Taotie, the beast that eats without stopping. He had died badly once, betrayed, and was born again into the same life with the bloodline stirring in him. He tracked down the people who killed him and killed them himself. After that the fighting was about his family, keeping them alive while the other races pressed in, and by then he was what stood between them and the rest of humanity. He keeps eating and keeps evolving, because the enemy does not stop coming.