I don't see a trademark association with the username darkrai097.
Darkrai's a pokemon, duh!
I'd never change my username. I remember some years ago I could use it everywhere without problems, nowadays whenever I try to create an account somewhere with that name it's already taken. So, I brush my ego with the fact that I may just have popularized that name, then again, I'd rather not since it's been stolen from me!! Argh!!
Tree. Simple, easy, memorable, awesome, green, life giving, etcetc hippie. Or PlatyPanda. I like that name as well. Oh, or LunaSol, I use that sometimes. Or Artemis, from my mythology phase. Or just plain Moon, since that is what everyone calls me. Or how about PlatyTreePandaLunaSolArtemisMoon. Actually, PlatyTreePanda sounds pretty nifty...
Moon... no. After thinking about it, I'd like for my username to be ElCubano or Gotti. If only I signed up for AG and some other sites a few years ago...