@Ashevelendar alo! Saw that one of your ideas had something to do with a character ending up in another world or universe, and that kinda fits with this whole world/ idea that I have:
Main idea: involves the existence of Paladins, people who have been assigned, by mysterious means that not even the Paladin herself would be entirely knowledgable about, the duty of protecting their world, or the safety of other worlds. They are given a Ring that provides them with the means to travel to other worlds/dimensions, and augments any latent magical or mutant ability the Paladin may have.
My go-to characters are Paladins:
1. Akire - an Empress living in a world called Amria, populated by a race of humans with long lifespans. The Ring gave her superhuman strength and a healing ability (to a degree; the more grievous the injury, of course, the more energy it needs to operate the magic). Legend has it that the royal bloodline was descended from dragons, and this may explain why the Ring augmented these specific abilities. The setting is typical medieval-high fantasy
2. Akira - a young girl born in a reality like ours. Only, she already was vaguely aware of the existence of other worlds, and of another version of herself (Akire). They do meet some time later, with Akire rescuing her from danger. Later on, Akira also acquires a Ring that gives her the ability to manipulate metal.