YEAH She is a Nexis being, She fought Lore (alternate Universe Wanda) due to that. Only other I can think of is Sise-Neg who popped in Dr. Strange books a few years ago. That Nexis being thing is supposed to be a big deal but it never really went any where. I remember a What If arc (Timequake) in which they touched on it but that was it.
The "TimeQuake" storyline in 'What If?' revealed a number of other Nexus Beings as Franklin Richards, Vision, Odin, Phoenix* and Kang, meaning that all of them are people who would have a counterpart in every possible timeline and alternate reality.
* - I don't remember them making it very clear if they meant Jean Grey herself, or the Phoenix entity.
It was touched on again in the Scarlet Witch miniseries, that a Nexus Being would always have some kind of powers, but there could be all kinds of variations across the multiverse, resulting in her having to battle Lore, an evil version of herself with necromantic powers, a "dark predatory variant" who was travelling between realities, killing her alternate selves and taking their power.