School Belle's Dragon: Devour, Evolve, Get Revenge

Su Han is a leading scientist and he has a dragon egg that his classmate Shen Sinian wants. He refuses to hand it over and Shen Sinian kills him for it. He wakes as the egg. Lin Wanxing, the campus belle, picks the egg up and the two of them are bound together by a devour evolution system, living as one organism; he eats whatever is in reach and each thing he consumes moves him further along. Early on that means small help, getting her out from under the harassment Shen Wei aims at her. Then Shen Sinian works out what the thing Lin Wanxing is carrying actually is and wants the dragon for himself, and starts using her as the lever. Su Han takes in a biological serum, comes out of it with control over fire, and turns toward the brother and sister, with the five-clawed divine dragon still far ahead of him.