Varen's Legacy is a craftable set available in all armor types. When you block an attack, you have a 10% chance to cause your next direct damage area-of-effect attack to deal an additional 3000 damage.
Varen's Legacy is part of the Dark Brotherhood DLC. The crafting station is located in the Gold Coast (Strid River's Artisan's Camp). You can craft any armor, weapon or jewelry of this set in any motif style you know, as long as you have 7 traits researched (per item). You can trade crafted pieces to other players. Each set item becomes bound on equip.