Hear me out. You want a character with genetic superpowers.
Sephiroth and Pyra/Mythra... probably can't procreate tbh.
Terry and Joker are normal people who either got lucky or trained for superpowers.
Banjo and Kazooie don't have compatable genetics.
Minecraft characters maybe don't repopulate either.
Byleth was granted superpowers due to spoilers, but not genetics.
THEREFORE
Min Min and Hero are the best choices.
Min Min definitely has genetics. Arms was very detailed about how the gene is passed on, so any babies she has are going to have like a 50/50 chance of having stretchy arms and another personality based superpower. In Min Min's case, it's the dragon arm.
DQ11's hero is also genetically talented,
coming from a royal knight on one side and the magically inclined king on the other. However, he has to actually learn through combat. It's a propensity towards superpowers, but he can't activate that propensity without fighting things. That being said, his superpowers are way more useful. He can magically cure wounds, remove diseases, and straight up raise the recently deceased.
So like... depends on two factors. What your genitals can do, and if there are combat encounters left on earth. Min Min is the pacifist's choice, Hero is there if there is combat to be had.
Official Emperor of this board. Bow before me, peasants.