Shalidor's Curse is a craftable set available in all armor types. While you are under 50% Health, dealing damage with a Light Attack heals you for 559 Health.
Shalidor's Curse is part of the base game. The crafting station is located in Eyevea. You must complete the Mages Guild main questline in order to access it. You can craft any armor, weapon or jewelry of this set in any motif style you know, as long as you have 8 traits researched (per item). You can trade crafted pieces to other players. Each set item becomes bound on equip.