Hacks.
All you need to do is get reincarnated and you get all the benefits of the curse with none of the drawbacks.
Create a chain of monsters consuming the souls of the next monster's owner. Then every monster's contract is fulfilled, but then the last guy in the loop kills the first guy, the one still wielding his soul. Then he reincarnates because of reasons, but his ghost doesn't follow him back in time. Then find the scientist guy and rinse and repeat, over and over. The cursed people didn't follow you, so they never suffered to begin with! Wahaha! Min-Max yourself in hyper-magic, then when you reincarnate the last time, you never need to rely on the curse to begin with. It's the perfect tunable groundhog-day boson laser as-a-person!