Siren of Purity

Lifelink, Forestwalk, Islandwalk
{1}, {t}, Sacrifice a non-token permanent: Gain 3
life and create a treasure token
{2}: Exile Siren of Purity from your hand: Target
land gains "{t}: Add {w}, {u}, {r}, or {g}" until Siren
of Purity is cast from exile. You may cast Siren
of Purity for as long as it remains exiled.