This quest was marked obsolete by Blizzard and cannot be obtained or completed.
In Winterspring, you will fight misguided creatures known as da Winterfall furbolg. Through the wishes of their leader, dey have gained incredible strength. If you wish ta gain the power a' da Winterfall, bring me da E'ko you find from dem.
Rememba, you must have the Cache of Mau'ari in your inventory if you want ta hunt for E'ko.