 
Instant
X can't be 0. 
 Target spell's controller exiles it with X delay counters on it. 
 At the beginning of each of that player's upkeeps, if that card is exiled, remove a delay counter from it. If the card has no delay counters on it, the player puts it onto the stack as a copy of the original spell.
Illustrated by Steve Luke
| Set | USD | |
|  | Tempest (tmp 61) | $0.94 | 
|  | The List (plst TMP-61) | $0.43 |