should he have one at all or be a monoformer?

In my AU, gladiatorial combat is part of life in Cybertron, and can range from "glorified bare fist boxing" to "pop culture gladitorial matches" kind of violent.

In the opinions of high society, these are considered "low brow" entertainment, but for many it's the only viable path to stable employment, and remains very popular.

Cy-Kill is the master of arenas from Kaon to Iacon, both legal and less-than-legal. He prides himself as a pit fighter who rose to the top and is one of the wealthiest bots in all of Cybertron.

Overlord is the circuit master of Tarn, a reflection of perhaps the greatest center of all things military in Cybertron. A living weapon of unsurpassed deadliness, they are actually two robots in one, a married couple by the name of Giga and Mega. They combine their arrogance, sense of superiority, and fighting prowess into one super bot.

Killmaster is the champ of the Iacon circuit. Convicted for deliberatley causing a collapse in a mine, he was condemned to the pets, and proceeded to become champ by being merciless, cunning, methodical and being oh so massive.

Straxus is lord of Polyhex, not just as a pitfighter, but also its actual ruler. Ancient rules of might makes right and right of leadership allows him much leeway in one of Cybertron's industrial hearts.