Boseiju, Who Shelters All
Legendary Land
Oracle Text
Boseiju enters tapped.
, Pay 2 life: Add 
. If that mana is spent on an instant or sorcery spell, that spell can't be countered.
Rulings (2)
-
Wizards of the CoastThe spell can't be countered if the mana produced by Boseiju is spent to cover any cost of the spell, even an additional cost such as a splice cost. This is true even if you pay an additional cost while casting a spell "without paying its mana cost."
-
Wizards of the CoastSuppose mana produced by Boseiju is spent on a spell and an effect creates a copy of that spell. The copy can be countered, even though the original can't.