Recha's Rite of Binding

Dragon creatures you control have first strike.
Sacrifice a Dragon: Add {r}{g}, and put a chain
counter on Recha's Rite of Binding. Activate only
once per turn and only if it has no chain counters
on it.
At the beginning of your end step, if it has any
chain counters on it, remove them all, draw a
card, then discard a card.