Yes, hypothetically, I think I can top everyone.

Research and development of time control, nanobots, creating infinities within a single moment, and cobbling together people's consciousness into a soul, even if nothing divine, linking every moment of their life together into one being.

When i have these capabilities, send the nanoswarms back in time, collect every moment of a person's life, and clone each moment of them by infinity.

Hook each clone of each moment of him or her to each other clone of every moment of the same person. Hook that "soul" up to a machine spanning an entire universe, maybe an infinite number of universes, that all spring up in an instant, following a fractal design making them all, essentially, computers. Each one gives pain, while enabling its victims to feel all that pain.

Torture everyone who has ever slighted me, even if they are now dead, with this infinite to the power of infinity exponentially painful god machine.

Also, destroy every good moment they ever had, and any trace of a timeline where they had it, so it simply didn't happen at all, regardless of time paradoxes.

Conversely, erase all suffering that ever happened, so it didn't even happen for me to undo and wasn't there to be undone, and grant infinite happiness and pleasure to all. Also dark imho, pleasant though it is.