Why's Pleasure Palace

(This card isn't a spell, and has "{t}: Add {g}.")
This card enters the battlefield tapped.
When this card enters the battlefield, sacrifice
it unless you pay {4}{g}.
{g}, {t}: Prevent all combat damage that would be
dealt to or by target creature this turn.
{g/u}{g/u}{g/u}{g/u}, {t}: This card and target creature
you control phases out (While it's phased out, it is
treated as though it doesn't exist. It phases in before
its controller untaps during their next untap step.)