C'Thiris Curse I

Description:
C'Thiris Curse I is one of the Skills in Portal Knights. Upon usage, the player sends curse damage to the selected target. There is a chance that the spell will rebound, however, and the player may receive the curse damage instead.

C'Thiris Curse I is a special Skill that is not attainable from crafting at the Altar. To obtain this Skill, you must complete the boss quest on Shrieking Sands. Speak with High Cultist Zeebo after completing the quest and he will offer to sell you the skill for 2000 gold coins.