Otherworldly Sliver

The casting cost of slivers is reduced by {2}.
Whenever a sliver enters the battlefield put
X time counters on it with X equal to its
casting cost. It gains vanish.
Whenever a sliver would leave the battlefield
exile it instead with X time counters on it, with X
equal to the slivers casting cost. It gains suspend.
If Otherworldy Sliver would leave the battlefield
transform it instead.