There are many worlds in the vast universe. Some with Magic, some in which dirt taste like candy, some where the laws of the world follow the logic of a Saturday morning cartoon. One thing they all have in common is a concept of Heaven, after all everyone and everything dies, evens gods die at some point so where do they go? Heaven, Hell, nothingness, it's all been thought of. What the majority of the cosmos thinks they know of the afterlife is wrong or at least partially so.
When someone dies the soul and memories that have been accumulated are saved forever in one big cosmic tank where the memories can be replayed, the soul gets to relive the good memories until the soul is fully healed once that is done the soul gets cleansed and sent off the be reused, the memories persist though and are kept safe in the event they are needed for inspiration or the occasional DeJa'Vu.
This happens in a world above all other worlds, a world called Heaven. It is a beautiful world full of color, the beings that inhabit it are various gods, devils, demons, angels and spirits. There have been conflicts in the past millennia ago but overall, it's peaceful and we all do our jobs maintaining the so-called afterlife of the souls and memories. Some beings have different jobs such as performing mercies, miracles, answering prayers or condemning others to name a few.
I was supposed to be a part of this wonderous world, this true Heaven. I was however betrayed though after my second 'year' of creation, by the ones I called my friends and family. All angels are given tasks that they are born to do, some I have already mentioned. Me, I was supposed to be an Angel of Death, the only being in the cosmos that are allowed and able to kill gods and devils and send them to their final resting place, after all everything dies. Many gods, devils and the those under did not want this but killing me would anger others and mess with the balance of the multiverse so they did what they could, they banished me to a lower world. One with no magic, no gods, no way to get back easily. A world of superpowers a world where I was supposed to never return from.