Schism Shard Crafting

You can craft Schism Shards acquired from the raid Killing Time with certain epic-level weapons to receive an upgraded or altered legendary weapon. Schism Shards are, and the crafted weapons are.

Crafting NPC
Varron Tertius 


 * Located in The Gatekeepers' Grove.
 * You have to complete Killing Time to speak with Varron and view the crafting recipes.

Ingredients

 * - found in the end chest of Killing Time as a rare drop. As of Update 41, they will also be available as a reward option in exchange for Time Runes. (Source: )

Base Weapons
Unlike most crafting systems, the base weapons capable of being upgraded exist across three entirely different quests from separate adventure packs:
 * White Plume Mountain
 * - Great Sword
 * - Quarterstaff
 * - War Hammer
 * Desire in the Dark
 * - Bastard Sword
 * - Great Sword
 * The Temple of Elemental Evil
 * - Scimitar

Sentient Jewels
Each of the recipes to upgrade or alter the White Plume Mountain weapons also requires that weapon's respective sentient jewel.

Upgrading Weapons

 * Base weapons must not have sentient jewels slotted into them. In order to use such a base weapon, the jewel must first be removed or destroyed.
 * Additionally, sentient jewels used as ingredients for upgrading must have 0 Sentience XP.
 * Note that with the White Plume Mountain weapons, each has an option of either a direct upgrade to the weapon, or an upgrade to a secondary weapon type. Be careful when making your selection!

WARNING: Any Mythic or Reaper bonuses the base weapon has will be lost on upgrade.
 * As of Update 41, players will be able to spend a new raid ingredient,, to add Mythic +2 or Mythic +4 bonuses to the upgraded versions of these weapons. (Source: )