The Time Gem

Indestructible, Affinity for Infinity Gems
{1}{u}, {t}: Choose a face up card in any zone that
was put into that zone this turn. Return that card
to its previous zone. If a card is put into its
owner's library this way, that player shuffles.
{5}{u}{u}, {t}, Tap two other untapped Infinity
Gems you control: Take an extra turn after this
one. Infinity Gems you control can't become
untapped until after that turn.