So it's an isekai novel about a guy wjo gets reborn in a mahical world. He is a sort of creation that looks like a slime who is the "child" of some evil god. As a blolb he can barely move so he absorbs a lizard like creature and gets multiple bloodlines. Each creature gets different blood lines and when he completes them by absorbing enough bloodlines he can transform into the baby versions of the creatures. He is the firstborn of the evil god so he gets to keep his memories, but there are other "children" and number 2 challanges him. 2 is a holy lion or something.