It's not my first Reincarnation

Magus and Wn-Lu sent out to kill the demon roaming around the street, but suddenly Wn-Lu stabbed Magus. Wn-Lu even admitted that he follows Demon Lord and anyone who comes in Demon Lord’s way he will kill them. In the middle of the street in front of many people he died, and no one even moved an inch to save him. After dying he got reincarnated in his past self, he got a chance to change his life and save humanity by avoiding the mistakes he made in his past life. But little does he know that the people he was serving was his real enemy.