Dialga

Roar of Time: At the beginning of each player's
upkeep, you may exile Dialga in the Space-Time
Rift. If you do, choose a phase of the turn. That
player skips that phase. Return Dialga under
your control at the beginning of the next end
step. A player who has skip a phase this way, can
not lose a phase in his next turn.
Whenever Dialga and Palkia are exiled at the
same time, roll a six-sided die. With a 2 or less,
the Cataclysm begins.