Infinite Evolution of the Serpent

Ethan has been reincarnated as a snake. The all-female serpent tribe that rescues him takes him for a runt born with no bloodline at all, and his sisters in the tribe look down on him for it. He has come into a system that makes him stronger with everything he swallows. He starts out in the mountains as a snake nobody has heard of, eating demon beasts and refining spirit flames, until the Flying Serpent bloodline wakes in him. He pays back the ones who looked down on him, and he puts the strength to use guarding the Azure Eyes, who took him in. He leads them out to take back the land that was theirs. The Serpent Matriarch stands in the way of that. First the road takes him to Celestide City, where the sects set themselves against him. He fights in the Hidden Dragon contest and comes away with a piece of red luck. One breakthrough makes him a demon king. A castle lord takes a liking to him.