Concentration

During your turn, you may pay {2} and exile a
card with concentration from your hand face-up.
You may cast it on a later turn as thought it had
flash for its concentration cost. When a card is
exiled this way, put 3 time counter on it and
remove one at each of your end step. If there is
no time counter left on it, put it into your
graveyard. You can only have one card exiled
this way at a time, exiling another card puts the
first one into your graveyard.