The Bonfire Blade

Whenever Equipped creature deals damage
to a creature, if that creature then dies,
sacrifice The Bonfire Blade. You gain an
emblem with "Whenever a legendary creature
dies, you gain a Cinder counter. If you have 5
or more Cinder counters, you gain hexproof and
creatures you control gain +2/+2 and
Indestructible."
Equip: Sacrifice a creature.