I'd pretty much handle it on a case by case basis. At the level our characters should generally be at, power is more of an abstraction.
@Zyx See above with mention to Gods. A description of what specifically your character does, and what they did to escape their world would be more relevant information.
Pretty much nobody cares what you get up to on your home World. If you start screwing people over in Heaven, then you tend to get your head cut off and universe annexed.
@Zyx "Peacekeeping" in a very loose sense of the word is probably what most Gods that live in Heaven are engaged in day to day. They are a fractious, overwhelmingly martial, and often short-tempered bunch, and duels among lesser Gods are a common sight. Minor Law Gods, Gods of Justice, Peace, and similar titles arbitrate disputes, end disturbances, and hunt down rogue Gods.
However...
Their standards are are dependent on who/what they swear fealty to. Pantheons are alliances of gods, but function like competing gangs within the city/multiverse. Small pantheons are like street gangs. Larger ones function like the mafia. The biggest serve as the functional governments and organized religions in Heaven.
So it's fine to say "I'm the god of XYZ" but without support to back it up it's a quick way to becoming "god of being a dead asshole" while someone with connections loots your universe.
I hope I'm getting across what a ruthless place the center of the multiverse is. Literally everything is at stake.
With the seeing the future thing, there is no past or future in Heaven. Time describes a process that happens within universes, Heaven is explicitly outside of every universe. So she has a good motivation for leaving, but she would find her foresight useless within Heaven.
Seeing the future of the Multiverse requires perfect knowledge of everything that exists, as well as everything that does not exist. The last God that tried it had her eyes burn out of her skull.
The thing with being an actual, functional God (as the title is understood in Heaven) is that it basically means you have a job. There's a function you serve in Heaven's multiversal society, and what that function is typically describes what you are the "god" of. Many Law Gods, judges and other judicators, exist within Heaven. In fact there are multiple, competing "pantheons" which pay homage to different "supreme" deities.
@Zyx An intrigue story set in Heaven's mean streets is something I would support.
@Zyx A fair cop, I think in previous instances I was getting too hung up on the fixtures of the setting, and lost interest as a result. We'll see about this one, I feel like player interest is going to be the main sticking point.
@trenenp I can work with you on it if you can describe to me what aspects of Malice you consider most important to the character.
@wikkit I wouldn't say it's fantasy-only but a sci-fi styled character would basically be pushing into Clarke's Third Law territory to stay competitive.