Hands down I'd take the job.

I'd wait a decade until we have many still waiting. Then I would announce the grandest of plans! A chance to choose their own method of execution, if they win the challenge. I'd gather all the condemned and equip them with the gnarliest weapons I can acquire (med evil only - no guns or explosives). Battle axe, sword, knives, anything of the sort. The condemned would be placed in their specific quarters locked in their cage with only one way out, into the arena. They would be preparing for the battle.

I would not allow any one else besides me to watch. No cameras, no outside sources, just me at the top of the citadel and the condemned waiting patiently in their quarters. I would stand overhead and yell out "TO THE DEATH!" and release the cage locks using an electronic controller at the top of my citadel next to me. The individuals would fight to the bitter end. With only one remaining, I would allow him the option of death, including waiting until old age if he or she so decided. The champion would be given good living quarters for his final day if that is the option he chooses, but will never be allowed outside these living quarters.

I continue to do this every decade. Until I am of very old age. Then after my 80th birthday and subsequent citadel execution, I would finally have the champion I will have been waiting for. The champion will come forward and yell up to me his method of execution: Death by one-to-one combat with The Executioner. Me.

I would prepare the citadel, and I would be the next one in the cage directly across from him. He will be wielding his weapon of choice and I will be wielding mine. I will have transferred the unlock switch to my cage, and would release it leading to the final champions method of execution. He would charge at me with his weapon and I would hold up mine: A note. The champion would slaughter me. I will drift into the abyss. The champion will have the key to escape to an uncertain fate for killing The Executioner. The note would be short and to the point. It would say: "I was the tool of death through my entire life. Thousands died because of societies failure to assimilate them. But death never left me. It waited patiently for the day it came for me. Today, I am the condemned. Tomorrow, you."