Since ancient times there has been a religious group worshiping three siblings of great power, each of them abnormal in appearance from our perspective because each of them are amalgamations of the forces they can summon to aid them. They've never really become a large group but they've never died off as the stories of their gods are passed along generation by generation. Tales of the Mutant, God of Combat, the Abomination, God of Transmutation and Evolution, and Deviantt, Goddess of Love.
These beliefs in these gods has survived on the element of truth they started from even until modern times. While other more well-known religions dominate the global population they haven't disappeared. But more and more people are leaving religions including this one, so in an attempt to get help and show they're right the leader began a ritual in an attempt to summon the weakest of the siblings. While the ritual was successful the leader of their congregation paid a price for the summoning of a being of such cosmic strength, as he didn't have sufficient magic to summon her dwelling within him, the magic in the area channels through him finishing the ritual but his body was distorted to look more monstrous, a manifestation of his deepest fears and insecurities.
As the confusion caused by the ritual subsided and time went on Elly, the Deviantt, still looking like a child after millennia upon millennia of traveling across dimensions, worlds, and universes, was found to be less of a goddess and more of a person in her own right, sure she wields a lot of power but she's a person nonetheless. Their cult's leader was the first to come to this realization and as they went from acquaintances, to friends, to lovers, they'd grown to understand each other much better. And they'd share stories especially Elly, having lived for countless lifetimes since the dawn of time in theirs worlds, just like her brother Entev, and her eldest sibling Fargo, having traveled together since ancient times she had many stories to tell, she may look like a child still but it's because she wants to be able to get away with occasional mischief, and a child like form is the best option for that, dispute her age being a number larger than any human could imagine.
Eventually they'd end up having a little girl, they named her Destiny and many other cosmic forces would be certain from the moment the learned of her, knew she was destined for incredible things. We're now on the eve of her thirteenth birthday, and things are about to change even if she hasn't realized it yet.