Boseiju, Who Endures

{t}: Add {g}.
Channel -- {1}{g}, Discard Boseiju,
Who Endures: Destroy target artifact,
enchantment, or nonbasic land an opponent
controls. That player may search their library
for a land card with a basic land type, put it
onto the battlefield, then shuffle. This ability
costs {1} less to activate for each legendary
creature you control.