A Masterwork piece is a Nightmare piece with extra power. It belongs to the same set as the normal pieces: a set of normal and Masterwork pieces in any mix keeps the whole Nightmare set effect (see Nightmare Armor), and every Masterwork piece you wear adds its own bonus on top. The whole set in Masterwork gives the full bonus below. The Masterwork pieces have the same P. Def. as the normal ones.
How to get it
From Chronicle 2, a Dwarf who crafts a sealed Nightmare piece has a 10% chance to make its Foundation instead. The Merchant of Mammon varnishes a Foundation into the Masterwork piece (A-grade Foundation - Masterwork) for the Ancient Adena that breaking the seal of that piece costs, and nothing else. A helmet, gloves or boots Foundation can become the Heavy, Light or Robe Masterwork, so you choose the kind at the varnish.
Heavy
| Masterwork piece | Adds |
|---|---|
 Armor of Nightmare - Heavy Masterwork | P. Atk. +1.2%, PvP damage +2.1% |
 Helm of Nightmare - Heavy Masterwork | P. Atk. +0.7%, PvP damage +1.2% |
 Gauntlet of Nightmare - Heavy Masterwork | P. Atk. +0.5%, PvP damage +0.8% |
 Boots of Nightmare - Heavy Masterwork | P. Atk. +0.5%, PvP damage +0.8% |
 Shield of Nightmare - Masterwork | M. Def. +2% |
Light
| Masterwork piece | Adds |
|---|---|
 Leather Armor of Nightmare - Light Masterwork | M. Def. +1.8%, Accuracy +1.25, HP Regeneration +1.8%, PvP damage +2.1% |
| Helm of Nightmare - Light Masterwork | M. Def. +1.1%, Accuracy +0.75, HP Regeneration +1.1%, PvP damage +1.2% |
 Gauntlet of Nightmare - Light Masterwork | M. Def. +0.7%, Accuracy +0.5, HP Regeneration +0.7%, PvP damage +0.8% |
 Boots of Nightmare - Light Masterwork | M. Def. +0.7%, Accuracy +0.5, HP Regeneration +0.7%, PvP damage +0.8% |
Robe
| Masterwork piece | Adds |
|---|---|
 Robe of Nightmare - Robe Masterwork | M. Atk. +1.1%, MP Regeneration +1.8%, PvP damage +2.1% |
| Helm of Nightmare - Robe Masterwork | M. Atk. +0.7%, MP Regeneration +1.1%, PvP damage +1.2% |
 Gauntlet of Nightmare - Robe Masterwork | M. Atk. +0.5%, MP Regeneration +0.7%, PvP damage +0.8% |
 Boots of Nightmare - Robe Masterwork | M. Atk. +0.5%, MP Regeneration +0.7%, PvP damage +0.8% |
Varnish cost
At the Merchant of Mammon, per piece:
| Masterwork piece | Foundation |  Ancient Adena |
|---|---|---|
| Armor of Nightmare - Heavy Masterwork |  Foundation Sealed Armor of Nightmare | 2,317,500 |
| Helm of Nightmare - Heavy Masterwork |  Foundation Sealed Helm of Nightmare | 594,000 |
| Gauntlet of Nightmare - Heavy Masterwork |  Foundation Sealed Gauntlets of Nightmare | 792,000 |
| Boots of Nightmare - Heavy Masterwork |  Foundation Sealed Boots of Nightmare | 792,000 |
| Shield of Nightmare - Masterwork |  Foundation Sealed Shield of Nightmare | 416,250 |
| Leather Armor of Nightmare - Light Masterwork |  Foundation Sealed Leather Armor of Nightmare | 1,739,250 |
| Helm of Nightmare - Light Masterwork | Foundation Sealed Helm of Nightmare | 594,000 |
| Gauntlet of Nightmare - Light Masterwork | Foundation Sealed Gauntlets of Nightmare | 792,000 |
| Boots of Nightmare - Light Masterwork | Foundation Sealed Boots of Nightmare | 792,000 |
| Robe of Nightmare - Robe Masterwork |  Foundation Sealed Nightmare Robe | 1,739,250 |
| Helm of Nightmare - Robe Masterwork | Foundation Sealed Helm of Nightmare | 594,000 |
| Gauntlet of Nightmare - Robe Masterwork | Foundation Sealed Gauntlets of Nightmare | 792,000 |
| Boots of Nightmare - Robe Masterwork | Foundation Sealed Boots of Nightmare | 792,000 |
The enchant bonus is the same as for the normal set (see Nightmare Armor). With the Masterwork chest, the set glows at a high enough enchant.