In Aion, you can PvP from like 11. You just use the portals to the other people's side.
If you want variety in your PvP, try EvE. If you want PvP with consequences, try EvE. If you want people to cry when you kill them, try EvE. If you want to blow up player owned assets valued at thousands of real dollars, try EvE.

14 day free trial, no CC required. 21 days with a buddy invite