Superhero

Gotham, City of Solitudes enters the battlefield tapped.
: Add , or to your mana pool.
, : The next time a creature you control attacks alone, it gains vigilance and +1/+1 for each creature your opponents controls.

House of Mystery enters the battlefield tapped.
: Add , or to your mana pool.
, : Remove target attacking creature from the game. Return it onto the battlefield under its owner's control during the next combat step attacking an opponent if able. It gains trample and flying.

Oa, the Center of All enters the battlefield tapped.
: add , or to your mana pool.
, : Until the end of turn, each creature you control gains +X/+0, where X is the highest toughness among creatures you control.

The Dreaming enters the battlefield tapped.
: Add , or to your mana pool.
, : Tap all untapped permanents and untap all tapped permanents. Activate this only once per turn.

The Hall of Justice enters the battlefield tapped.
: Add , or to your mana pool.
, : All legendary creatures you control gain double-strike, lifelink and hexproof until the end of turn. They must attack this turn if able.

The Hellfire Club enters the battlefield tapped.
: Add , , or to your mana pool.
, : Tap target permanent. If it becomes untapped before its controller's next untap phase, gain control of it.

Xavier's, School for Gifted Youngsters enters the battlefield tapped.
: Add , , or to your mana pool.
, : Until the end of turn, each mutant you control gains +1/+1 for each other mutant you control. Untap them.