Walker Mate

When Walker Mate enters the battlefield,
until end of turn, you may activate any ability
of up to one Planeswalker you control, as
though you had the loyalty to do so. If you
activate an ability this way, the Planeswalker
will remain in play with loyalty as though it
was just cast. This doesn't count as a
traditional loyalty ability. Play this ability
as a sorcery.
At the beginning of the end step,
exile Walker Mate.