Bone of Contention Card Rules
 

Can you play the Bone of Contention card with only one monster in play? It says to play during any combat, but it sounds like it expects 2 monsters.

In a game now and someone is pretty mad that I played it haha.

Would it make the one monster basically void and the player get the treasures and no levels, or does the player have to fight a monster and win in the same combat?