Question: who fulfills the prophecy in the originals?
Answer: According to the prophecy, the mikaelsons must die. The prophecy said that- if the prophecy is fulfilled, mikaelsons will all fall, one by foe, one by friend and one by family(not the exact wordings). Now the one who tries to fulfill it was Lucien but he was not able to do that because he was killed by mikaelsons.