As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.
When Seraph Sanctuary enters the battlefield, you gain 1 life. Whenever an Angel enters the battlefield under your control, you gain 1 life. {T}: Add {C}.