Treasure Hunting Through the Multiverse

A boy gets reincarnated into a cultivation world and lives his life peacefully after becoming the strongest. Just when life was good, a huge humanoid black fog thing attacks the world and he had to sacrifice himself to defeat it. Only when he was getting ready to go to either hell or heaven, a system merges with his soul, informing him that the creature didn't die and come again, to attack the world and his loved ones. So, he goes to another world, with a system, to stop that creature from harming his loved ones. All he has is a system which gives him rewards when he opens treasure chests. I changed both the cover and the title as I thought the previous ones weren't that good. The new ones are also not great though. Points to remember while reading: 1.The cover has Nie Li from TDG on it. That means my MC looks exactly like the Nie Li from TDG. 2.I did write harem, but I will make sure it doesn't become similar to the pokemon game and be more like the pokemon show, where Ash bonds with the pokemon and makes the pokemon join willingly. 3.This is going to be a multiverse fan-fic and he is going to many other worlds. 4.A close person of the MC will die. Most probably, there will be no more deaths, well at least till the story in my head. Many readers didn't like it, so I am giving a heads up to the new ones. 4.I am not writing a story for an English textbook. There will be errors and grammatical mistakes. Please bear with me and if considerate, you can correct them and I will make changes. 5.I am writing this, only to feel better and deviate my. mind from studies so, don't expect steady updates. 6.And lastly, I don't own anything except the MC. So, if I use something which the owner is not comfortable with, let me. know. somehow and I will remove it.