Ready for my hot take? Muscular is an ill fitting villain in the world of MHA, and his role in Kota's backstory is unneeded. You don't even need a villain to kill Water Hose. Just maybe a tragedy of a collapsing building being evacuated that happens to have Kota's parents die saving the lives of others. You get his bitterness towards pro-heroes without needing the biggest caricature of a brute in history. Muscular hardly fits in the LOV aside from reminding the audience that, "Yes, the League of Villains are the bad guys." The other members, Shigaraki, Dabi, Toga, etc. have these supposed tragic backstories driving them to villainy, regardless of it being excusable or not. But with Muscular, he's got no backstory. Stain is an insane fanatic who operates on pure self-delusion, but at least he has some depth. Even Overhaul had some drive of his boss saving him from hell. And when the POS who disassembled Eri repeatedly gets more depth than Muscular, that's a sign how the brute fits inside MHA less than freaking Zavok does in Sonic.