Text (LG+errata): Counter target spell. At the beginning of your next main phase, add {X} to your mana pool, where X is that spell's converted mana cost. [Oracle 2003/07/01]
The mana gain is done as a beginning of main phase triggered ability and not as a mana ability or such. [D'Angelo 2000/03/03]
If used after your first main phase but before your second, you will get the mana during your second main phase. [D'Angelo 2001/02/10]
Legacy tournaments (see Rule 911) have banned this card since 2004/09/20.
Extended tournaments (see Rule 913) have always banned this card.
