It's Not Easy Being Green - S3.E16

With Rumplestiltskin as her slave, Zelena challenges Regina to a fight to the death and shocks the Evil queen with the reveal of their familial connection, and the town lays Neal to rest. Meanwhile, back in the past in the land of Oz, a jealous Zelena asks the Wizard to send her to Fairy Tale Land after discovering that she has a sister, Regina, and that Rumplestiltskin is training her to become a powerful force to be reckoned with.