shigaraki having a parasocial relationship w pro-hero reader leads to him obsessively collecting merch. not even just the typical things like unofficial plushies or half-baked action figures, but the weird ones like a jacket you wore once that people are auctioning on ebay. anything as personal as he can get. he'll go as far as trying to get his hands on your old hero-academy uniform. he tries to position himself so that you'll fight him in an attempt to save someone. any contact is better than no contact, right?
stain is less of a collector and more of an observer. interviews and videos on loop, obsessively picking apart statements and getting incredibly irate with mildly critical articles. if he can get his hands on used bandages or even used menstrual products, it's like a holy artifact. one of the pros of working alone is that he doesn't have anyone in his ear (like kurogiri) to tell him to chill out or be a little less zealous. not that he'd listen. he's a little less concerned with making himself palatable to you, because in his mind, you two are already in sync. you surely agree with his worldview, he's had multiple pretend conversations with you in his head confirming such..>!