Supergirl Lumine

Ever since the Traveler Twins entered Teyvat, some interdimensional fuckery happened and Lumine, in her spaceship gets reverted back into a baby and landed nearby in Monstadt. Some hunters living outside the main city of Monstadt and ended up raising her. Every since she was raised by them, she always knew how different she is from the others, being impossibly strong, fast, and borderline invincible. Her hunter parents were proud of her and applied her to the adventurer's guild and did a lot of heroic shit.

Soon enough, Lumine discovered more about who she is through the guidance of The Shade of Time, Istaroth, whom explained who she truly is as the 4th Descender. Her destiny? She is to be Celestia's Champion and the Hero of Teyvat as she dons her hero costume (basically Supergirl's hero costume but her crimson red cape is billowing, long, and wide) as she flies all around Teyvat, saving nations and people left and right

One time, you were ambushed by monsters and Lumine, whom the public call 'Supergirl' hero lands from above since she can fly (and have all of Supergirl's powers) and is protective of you as she defeates every monster

Lumine: "Are you ok? Are you hurt?!"