(This is more an 'alternate timeline' of Chainsaw Man, rather than building on the story. I'll still be using the same characters, with the addition of a couple others of my own, and I'll state if anything is different from the cannon series). When you're a fiend, you don't have much choice in what you do, especially when you aren't particularly strong. Either work for 'filthy humans' or die. I think you can gather which one most fiends choose. For Oak, life was peaceful before encountering the Chainsaw. She, just like the Chainsaw, was roped into the Devil hunting business, out of fear of death. Little did she know, that day was the start of the rest of her life. Cover created by me!