i did this yesterday again, what i did was:
get in your king to start it, move as many pieces in front of him and the queen as you can, pawns and wolves mostly.
Then get in the warlock (queen) and nuke the other king, he should be close by then. if you need get a second character in a healer to heal your king.
Only issue i had was when medive would "cheat" and put fire under my king multiple times. you can heal through one fire no problem.
If done right the other king will never make it to yours and you will just nuke him down.

In the chess event the fewer toons you control the better because the ai will control the other for you.