The Colosseum boss that requires you to complete the Colosseum (as in win and get a ring) ten times before you gain access. He drops a token that can be turned in for a spell casting statue, a token that can be turned in for xp or an augment gem, and also the title "Immortal Champion".
Note: He continuously spawns platinum golems and spawns several other golems called "Guardians of Deimos". He has extremely high HP and it takes a while to kill him with a small group which due to restrictions on entry is all you'll probably have.
You give Master Arbitrator Gladiator Diemos Token.
Master Arbitrator tells you, "I see that you have proved you skill against the Champion, Gladiator Diemos. Well done indeed. I hereby grant you the title, Immortal Champion."
Master Arbitrator tells you, "In addition to your new title and this useful hook caster, I'll also give you a token that you can trade back to me for a great deal of practical knowledge, or you can trade it in to Fiun Rehlyun at the Fiun settlement in the Halaetan Isles for a blank Augmentation gem. A difficult decision, I know."
Master Arbitrator gives you Gladiator Diemos Statue.