A huge clock tower, the clock literally controls time for the surrounding area. If it happened to break then that area would simply, fade from existence, lost to all but time travelers, most of which would want nothing to do with two warriors trapped forever in time. Ageless, deathless, the battle would continue forever, however, the tower is made purely of steel and brass, and heavily enchanted, it is incredibly difficult to cause damage to, let alone ruin its ability to tell time. There a time pockets splayed among the inside of the clock, areas marked by a lack of colour, for the areas in which time has frozen, or by a visually noticeable slow or increase in the movement of cogs in comparison to the rest of the clock. One with a good eye can easily pick out increased or decreased time areas, though it takes a well thought out plan to use them to your advantage. Of course a time user could draw energy from the pockets of disturbed time flow, possibly even correct them, but seeing as there are no time users in the tournament, they would be of absolutely no use to people other then strategies they can build around them.
The fight will take place inside the massive, pure metal clock tower, they will meet on the central timing cog, spinning at a steady rate in perfect beat, matching the "Tick Tock" of the clock perfectly. It sits horizontally in the center of the tower.

NOTE::. If you enter an increased or decreased time area your character will recognize that as normal time and everything else will change based on the time pattern you have entered. If you go into an area with 3 times as fast time speed, your character ages three times faster then in normal time, but as long as he is in the increased time zone it appears to be normal to him. Be weary with the side effects of every time area you enter.