: Add 
in its mana cost, X is considered to be 0.Cursed Mirror can enter as a temporary copy of a creature on the battlefield, with haste, before becoming a red mana rock after the turn ends. That gives it an immediate value opportunity beyond ordinary acceleration. The copy can use entry abilities, attack if appropriate, or use a tap ability without waiting through a turn cycle.
Copying Eternal Witness can recover a card, while copying a useful opposing creature can adapt the artifact to the current board. The copy choice does not target. Legendary status is still copied, so duplicating your own legend requires attention to the legend rule. When the copy effect ends, Mirror remains available for its normal red-mana ability rather than disappearing with the temporary creature form.
Artifact packages work well when their pieces have useful roles outside the largest combo. Sensei’s Divining Top supplies selection, mana rocks support development, and a specialized payoff can finish a turn once the other resources are available. Consider which piece the current hand is missing before investing in a search or recovery sequence, especially when the artifact still needs to be cast afterward.
Check the copied creature’s actual abilities before choosing it. A large creature may offer an immediate attack, while an entry effect can provide value without combat. Counters and most temporary bonuses are not copied, and copying a creature does not produce any ability that triggers only when that creature is cast.
