Highest I got was 200 or so before I got bored and ended it. I believe the combo was 2 or 3 Pegasus Riders with Spicy Carrots, Premium Horseshoes, and a Bannerman. I would be able win turn 1 on almost any setup unless there was a spiked shield. The few times I got unlucky, I could just throw an item to settle it.

I got to ~273, then I died because I was a bit bored and tired so didn't play my strategy and just made some moves. Didn't pay attention when the enemy took my blade dancer and used the relic to become a blade dancer. Next move I thought I was safe enough but the blade dancer did blade dancer things and captured my king from across the map :)
I was just playing the game out and was planning on using a "restart timeglass" to 1-2 move instagib the enemy once I had compromised my position enough and when the game seemed impossible.

I was using bannerman + martyr + 2 blade dancer + 3 queens. Both blade dancer and martyr can't capture with bannerman, but I had relic to start with 2 moves so I could move both next to the enemy and kill on the 2nd turn regardless of which piece they decided to capture. Martyr next to the enemy king is insane, if they take then either blade dancer can jump over pieces to direct capture king (so spiked shield isn't a problem), or one of my queens can capture their king from my side through the hole they left in their defenses when martyr blew up. And if they take blade dancer then martyr captures and either blows up on the enemy king because of the spiked shield or the enemy is forced to capture my martyr because it is next to their king. And if they try to move away then my martyr with boots moves faster than their king and can just capture it anyways, but it rarely comes to that because AI just suicidecaptures my martyr.

I had like 50 restart items and gaining them faster than I used them. If the board state wasn't good for a 2 round capture I could just use one to instantly re-roll positions and win, so I could have kept going to infinity if I didn't play recklessly.

I still hope for some further content updates. Would be awesome to get the Champion and Wizard from Omega Chess and maybe the runs can be expanded a little more.