he went back to his home planet
These are the fates of all the known Arbiters:
Fal 'Chavamee: Fal & Harka stabbed eachother with energy swords.
Ripa 'Moramee: Killed with his own energy sword by Sgt. John Forge.
Reach Arbiter: ?
Thel 'Vadam: He went back home to Sanghelios after the memorial service.