Horikoshi sucks as a writer and to be honest what would be a big shock just fizzled out because there was no foreshadowing aside from there was a traitor in UA which no one seemed to have brought up again.

MHA had a great premise and I was liking the quirks but it just got shitty.

Villains have op powers while heroes have so many downsides they may as well not have them.

Hori has a track of failed mangas and it shows how he always just fizzles out because while the start is great he either loses interest or any creative power in how to continue a story.

Look at Stars n Stripes, got an op power but then we wall of text showing their downsides and how Shigaraki has plot armor out his ass.

Hagakure was a lazy choice for something he probably forgot until he took a shit thay morning and someone mentioned to him about the traitor at UA.