The way the writers treat certain dynamics in this show is genuinely disturbing and unfair to me. In this essay I will talk about Mylo and Powder vs Vi and Mylo.
The framing to how Mylo acts towards Powder when she messes up is always serious, dark, angled to make Mylo seem like the asshole. As if his being mad at his kid sister for sabotaging her older siblings for the umpteenth time is totally out of line and invalid.
Meanwhile, we have Vi who is much more verbally and physically abusive to Mylo. Any time she does something to him, it's framed as funny, humorous, as if "haha Mylo is such a dick and deserves this 🤭".
To recap, Vi:
Kicks a door open that Mylo is actively working on, with no warning, scaring the shit out of him. Mylo is left locked into place, curled on himself until he's swatted in the head by Claggor to bring him back to earth. No wonder this poor kid has anxiety.
Passively insults Mylo while they raid Jayce's apartment, accusing him of "filling the bag with junk" as if she knows jack what to look for, either. As if Claggor didn't dump a drawer full of "junk" into their bag. Powder knows what these fancy rich folk toys are because the plot demands it and Mylo has to look dumber for it.
Kicks him down a drain pipe. KICKS him. Face first. And this is framed as so super funny because he didn't want to get his new shirt dirty. And don't @me with "he was wasting time" when actually, Mylo could have fallen on his head/neck and been seriously injured or worse, not to mention if Claggor fell on him (as he kinda does anyway). Or something toxic got in his mouth on the way down. This is the only time plot armor saves him, because teenagers could probably just walk off being put through a wood-chipper, and he has to die for his sister's character development later.
Criticizes Mylo for having the audacity to speak up about Powder being a liability, because she has no argument of her own against him. Physically intimidates him and tells him to shut up. It's a little funny I guess, but the blatant fear in Mylo’s eyes feels telling. This likely isn't the first time Vi has threatened him, or even deliberately hurt him. Because she's hot-headed and can only deal with her problems with violence.
Meanwhile, Mylo:
Has been deeply annoyed at Powder because she's a frequent liability, and calls her out. If she's going to go on important heists with her older siblings, she needs to be held just as responsible when she messes up and she isn't.
Is further annoyed that Vi would frequently give her a pass for every transgression, while invalidating him in return. He's too young to realize he should be more miffed at Vi for all her bs, but he looks up to her, and the resentment turns back to Powder.
Picks on Powder occasionally because he's an older sibling and it's extremely normal behavior. What a nightmare.
Vi is so clearly the bigger bully here, but she and Powder are main characters granted privileges and angles that cannon-fodder like Mylo are not. We're supposed to sympathize with and side with Vi because we see more emotional beats with her, and because Mylo is "mean" to her baby sister, the audience at large will be on her side. Even if Mylo’s own little arc is on display (if people would open their eyes, anyway) and we can understand and appreciate his totally valid feelings at the end of the day, his behavior won't be framed as any way positive like it is for Vi. Mylo’s negative behavior has to be framed the way it is or it won't seem as serious when jinx hallucinates him later. If the roles were swapped, it would be Vi's abuse ringing in the back of Mylo’s mind had he gotten to adulthood, causing severe damage to his psyche. But unfortunately it's not about him.
Vi was infinitely worse to Mylo than he was to Powder. It's genuinely fucked up the way she treats him is framed as funny and deserved while his justified bitterness toward Powder is framed as terrible and makes Mylo nothing but an asshole for it. He wasn't even given the chance to grow out of it, making his lasting impression almost entirely negative to those refusing to see nuance in his character.