Batman is required in all matches of challenge battle 4. A glitch in the expert stage causes it to not recognize Batman/Beyond Animated as a Batman character, although he does work for the standard and nightmare stages.
Challenge: Countdown! (You only have 2:30 to defeat your opponents)
Challenge: Regeneration! (The enemy team heals by ~1% of their maximum health per second)
Challenge: Radiation! (You lose 1% maximum health every second)
This match awards 3 energy cards.