From Fatty to the Supreme Demon Lord

What do you do when you die and wake up in the body of a powerful entity? Leo was chosen by the Demon Lord and killed for that. He awoke in his new slim and attractive body, an opposite image to what he looked like before dying. He thought the new world would now be his to take, but was baffled when he learned that all the power his predecessor had was locked behind his life's sigils. Such a revelation could have broken anyone, but he's determined to gain power to unlock more power. He's determined to have this new world know him for what he can achieve, and he won't tolerate any humiliation as in his past life. But, the gods are waiting for him. Waiting to...end him. What to expect; *Progression *A rude system/guide/pet *A not-so-righteous MC (not a villain) *Murder *Love(slow burn) *smut