Gladiator's Arena

When the Gladiator's Arena is summoned all creatures on the battlefield may only target Gladiator's Arena, instead of select player or Planeswalker. When Gladiator's Arena is attacked any player may defend it with creatures inside the arena, or join in the attack.
If a player wishes to summon a creature place
it face down and tapped until Gladiator's
Arena is destroyed.