Grey ruins falling into darkness, even with sunlight still shining in the sky

Boseiju, Who Shelters All

Boseiju, Who Shelters All enters tapped.
{T}, Pay 2 life: Add {C}. If that mana is spent on an instant or sorcery spell, that spell can't be countered.

Grey ruins falling into darkness, even with sunlight still shining in the sky.

Tales of Middle-earth Commander

Isengard, Saruman's Fortress enters the battlefield tapped.
{T}, Pay 2 life: Add {C}. If that mana is spent on an instant or sorcery spell, that spell can't be countered.

Secret Lair Drop

From the Vault: Realms

Boseiju, Who Shelters All enters the battlefield tapped.
{T}, Pay 2 life: Add {1} to your mana pool. If that mana is spent on an instant or sorcery spell, that spell can't be countered by spells or abilities.

Suppose 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.

The 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."