Collect the Heart of Kuruk, the Trunk of Autuk, the Twig of Loruk, and the Roots of Hanuk. Part of this quest happens in Frostwall, Shadowmoon Valley, Gorgrond, Spires of Arak, Nagrand and Lunarfall.
Upon completion of this quest you will gain 2 850 experience and will receive Treessassin's Guise toy.
Here you can buy Legacy of the Ancients Boost for EU or US Servers.
You'll get guide for completing Legacy of the Ancients Boost