Lou (luna (ocverse))

When Lou was a kid, they were not born with magic (even though both of their parents were) and because of that they considered Lou to be useless and didn't care for them when they were growing up.

For most of their life they were actually raised by their aunt, who also didn't have any magic so they found comfort in that and in her (obviously she dies. canon compliant)

After her death, Lou's parents actually put the blame on them, saying that their aunt was alone with them when she died and that they could've had saved her if they had magic. 

Because of that, Lou develops a lot of self loathing and guilt and decides to run away from their home trying to seek a way for them to gain any sort of magic or anything that could make them more useful to others. 

At some point they meet Ru Shi who teaches them about plants. And  Lou realizes that they can become useful by learning how to use plants to their full extent.

Ru Shi is the only one Lou trusts and they have deep jealousy for anyone else who possesses magic...(loukanna strangers to friends to lovers 999999999K words slow-burn which will kill u.)

They learned to trust and look up to Ru Shi over years because she showed them a way to save themselves from feeling powerless and also because she has a genuine way to use her magic, which is what Lou wanted for themselves.