Nivix, Aerie of the Firemind
Land
Oracle Text
{T}: Add {C}.
{2}{U}{R}, {T}: Exile the top card of your library. Until your next turn, you may cast it if it's an instant or sorcery spell.
Watch Out
Mana abilities don't use the stackRules Note
If this card's activated ability produces mana and doesn't target, it's a mana ability. Mana abilities resolve immediately without using the stack — opponents can't respond to them. However, abilities that target (even if they produce mana) aren't mana abilities.