The Episode 42: Legion of Doom Title update for DC Universe Online has 3 achievements.
Defeat Ultraviolet Sinestro without taking any damage from his Ultraviolet Construct's Explosions in the Umbrax the Ultraviolet Duo (Normal or Elite)
Defeat the Batman Who Laughs without using a consumable or Supercharge ability in The One Who Waits (Normal or Elite) Alert
Defeat the World Forger without any players failing to block the Energy of Creation from his anvil in The Sixth Dimension (Normal or Elite) Raid