Integrity // Intervention

A split card's characteristics are a combination of its two halves while it is not on the stack. For example, Assault // Battery has a mana value of 5 while it is in your library. If an effect allows you to search your library for a card with mana value 4 or less, you can't find Assault // Battery.

If an effect allows you to cast a spell with certain characteristics, consider only the characteristics of the half you're casting. For example, if an effect allows you to cast a sorcery spell with mana value 2 or less from among cards in your graveyard, you could cast Assault this way, but not Battery.

Split cards have two card faces on a single card. The characteristics of the half you didn't cast are ignored while the spell is on the stack.

If the chosen target is an illegal target by the time Intervention tries to resolve, the spell doesn't resolve. You don't gain 3 life.