Heroes always take turns before the Overseer during the Battle Phase. Rounds continue until all monsters in the room are destroyed or until all heroes are dead.
Turn order goes as follows:
1. Players take turns by performing one action for each hero they control. Players always decide the turn order for the heroes. An action counts as either using a hero’s shot sequence or playing an Item, Spell, or Ability card. Players may never do both in a single action (unless a card overrides this rule or a hero uses a Combo item).
2. After all heroes have taken their turns, the Overseer takes one turn for each monster. A monster’s action is the shot sequence depicted on its Monster card.
3. After all monsters have taken their turns, the round ends. Check if any additional end of round effects have occurred.
4. A new round begins.