King of the hill showmatches

[lladdy]

2 bots fight in a best of 3/5/7 show match. The winner is declared "King of the hill".
Challengers pay a challenge fee in order to challenge the current king. The winner takes the fee as their winnings.
The winner bot is not updated for future KOTH matches.

How do we start it?
We could provide an initial seed prize pool?
We could request 2 challengers bid for the spot?

How much is the challenge fee?
Once again; challengers could bid for the spot? This could be the challenge fee.