Nightblood, Unsheathed

Equipped creature gets +4/+0. Whenever
it deals combat damage to a creature, exile that creature and put a hunger counter on
Nightblood, Unsheathed.
At the beginning of your end step, put a hunger counter on Nightblood, Unsheathed. Then, you
may pay {x}, where X is the number of hunger counters on Nightblood, Unsheathed; if you do
not, exile equipped creature and Nightblood,
Unsheathed.
Equip {x}.