Okero's Burden

Whenever a creature you control dies, put a weight counter on Okero's Burden.
When Okero's Burden is put into a graveyard
from play, create X 1/1 colorless spirit samurai creature tokens with bushido 1, where X is number of weight counters on Okero's Burden.
{b}{g}, sacrifice Okero's Burden: Regenerate all creatures.
"If only we had known."