>>51763362I buy my own Pokémon merch and other trash, and if anyone ever did anything to anything I own and got with my own money, I'd flip out.
My mom doesn't really understand my pokémon junk collecting but she would never damage my belongings to get at me.
Also if you're underage (which op sounds like he is), even if you can't buy stuff and your mom is burning your belongings, that's still abusive as fuck.
Easy solution though. Get a job, move out, and buy as much pokemon trash you want to. If you can't move out you can also just start locking your room door/locking your stuff away.