To beat the centaur, we must use their hatred against them.  We will ally with one of the clans and through them, we will learn how to defeat all the clans.$B$BIf you choose to ally with the Gelkis then slay their most hated rival, the Magram.  After you earn the respect of the Gelkis, meet with the Gelkis shaman Uthek the Wise, on the outskirts of the Gelkis Village, in southwest Desolace.