Seed of Evil quest in Aion is easy only if you are lucky. The drop rate of Crest of Lepharist Revolutionary is very low. I hunted more than 40 Lepharies until i get one. The mob that droped this quest item for me is a thief near the boss. Lepharists are found at Belbua's Farm.

The steps for Seed of Evil quest are:


1. Talk with Xenophon in Sanctum.
2. Kill Lepharies Thiefs, Peons and Shamans until Crest of Lepharist Revolutionary drops.
3. Return to Xenophon for reward (12000 XP, 4100 kinah).