There's a small chance he might just be a troll like IceRulerKing. I would recommend just leaving these kinds of people alone because confronting them or calling them out might just be what they feed off of.
Something's never change so they?
What I don't get is he is asking for someone to unblock him dispite the fact he is claiming anyone but the person who blocked him is better at gmod/sfm... or so I saw on this Seth's info on his page before I blocked him...
He just wants attention.
This is why I block him. Jeez