Dark Matter is an extremely rare item only available through chests, the bazaar, the clan shop after achieving the highest clan ranking, and through stealing from The Undying during the final battle. Dark Matter is incredibly powerful in that it adds up all of the damage from Knots of Rust dealt since the last time a Dark Matter was used, and deals that damage all in one hit, up to 60,000 damage.
The damage of Knot of Rust is (caps at 9,999):
DMG = Current HP / Random(1~10)[1]
The damage of Dark Matter is the sum of all Knots of Rust (and Devour Soul) that have been used divided by 3. Damage caps at 60,000. Devour Soul is an attack used by the Esper Shemhazai when summoned that is essentially the same as using a Knot of Rust.
DMG = SUM (Knot of Rust DMG) / 3 + SUM (Devour Soul DMG) / 3 [1]
The counter resets to 0 after each use. Shemhazai's special attack, Soul Purge, has exactly the same effect as Dark Matter and using it also resets the counter. Dark Matter's damage is unaffected by Reverse and has the maximum effect capacity, which means no other spell or technick can be performed simultaneously.
Dark Matter can be made in the bazaar by selling one Bat Wing, three Grimoire Aidheds, and three Grimoire Togails. Also, the sixteen chests on Phon Coast and the sixteen chests in the Necrohol of Nabudis correspond to each other. The Zodiac Spear can only be found in the Necrohol of Nabudis, meaning if the player claims the chests on the Phon Coast before obtaining the spear, it will be forever lost. However, if the player is to open the chests with the Diamond Armlet on, they will all contain Dark Matter instead of Knots of Rust. The chests can be claimed in either Necrohol of Nabudis or Phon Coast, and once claimed, will disappear from both locations and will never respawn. It is recommended the player first finds the Zodiac Spear, and claims the other chests later with the Diamond Armlet equipped to get the Dark Matters.
A good place to farm Dark Matters from treasures is in the Cloister of Distant Song area of the Necrohol of Nabudis, but the player must have the Diamond Armlet equipped.
