Dark Matter (Japanese: ダークマター Dark Matter) is the main antagonist of Pokémon Super Mystery Dungeon.
Dark Matter is an entity born out of the negative feelings of all the Pokémon in the world. By absorbing a Pokémon's life energy, it has the ability to turn them to stone. When a Pokémon's body is turned to stone, its spirit is sent to the Voidlands, a dark realm swarming with Void Shadows, Dark Matter's minions capable of taking on the form of Pokémon. Dark Matter is also able to possess Pokémon that have even the smallest amount of darkness in their hearts. Using its mind-controlled slaves, Dark Matter turns Pokémon to stone to absorb their energy and grow stronger. Its ultimate goal is to "return the world to the void", namely to cause its spinning to stop and make it be consumed by the sun. It attempts to accomplish this by absorbing energy from the Tree of Life, the source of all the life in the world.
A long time ago in the past, when Dark Matter first surfaced, Pokémon fought against it to prevent their world from being destroyed. Alongside those Pokémon, a sole human also joined the fight. Due to the stars aligning just right in the sky, Dark Matter was finally defeated. However, the negative feelings that Dark Matter was made out of rained over the world, ensuring that Dark Matter would one day rise again. The ancient Pokémon, foreseeing this, prepared certain countermeasures for the future, such as sealing a spring of Luminous Water on the top of Revelation Mountain, holding the power to turn Pokémon back from being turned to stone. Mew, a Mythical Pokémon who had acted as a leading figure during the battle against Dark Matter, sent its spirit into the future to be reborn during the era in which Dark Matter would resurface.
During the events of Pokémon Super Mystery Dungeon, Dark Matter is first mentioned by ancient writings in the Voidlands, where the player, their partner, and most of the Expedition Society are sent after Nuzleaf, Yveltal, and Beheeyem possessed by Dark Matter turn them to stone after the player breaks the barrier over Luminous Water spring on Revelation Mountain. During their journey through the dark realm, they also learn bits of the past and come to understand bits of Dark Matter's history.
Later, after the player and their partner return to the real world, they rejoin with their remaining allies, and eventually make their way to the Tree of Life, which is withering and dying due to Dark Matter's influence. After defeating Dark Matter's minions, the group witnesses as the Dark Matter causes the Tree of Life to lift into the air and start flying away from the planet, meaning to pull both the tree and the planet into the sun. However, thanks to the combined efforts of multiple Pokémon, including Deoxys, Rayquaza, and Mewtwo, the tree's ascent is significantly slowed down, giving the player and their partner time to reach Dark Matter. After Arceus teleports the two to the Tree of Life, their Harmony Scarves cause them to evolve to their final stages for the third time, protecting them from the cold temperatures and thin air in the stratosphere. While climbing the tree, the duo encounters Nuzleaf, Yveltal, and Beheeyem, whom they free from Dark Matter's binds.
Ultimately the player and their partner confront Dark Matter at the top of the Tree of Life, where it traps them into a pocket dimension of its own making. Knowing that the tree isn't completely dead yet, the duo engages Dark Matter in battle. However, just when it seems like they have almost won, the Tree of Life finally runs out of energy, allowing Dark Matter to regenerate itself, assuming a new sphere form to protect its core, while the player and their partner are forced to revert to their original stages and all their current emeras are lost. Although Nuzleaf, Yveltal, and the Beheeyem try to attack their former controller, they all end up being turned to stone. Despite initial discouragement, the player and partner start fighting back, revitalizing the Tree of Life and engaging in yet another battle against the Dark Matter, breaking it down bit by bit. When its core is finally exposed, Dark Matter tells the duo how simply breaking him would cause him to be born again in the distant future. Surprisingly, the partner still is ready to break Dark Matter, accepting its negative feelings as a part of how the world works. The partner strikes Dark Matter's core one more time, causing it to burst into pieces, faintly thanking the partner for accepting it.
Afterwards, Xerneas, the incarnate form of the Tree of Life, reveals that Dark Matter has now completely disappeared, having turned to sparkling light that faded into nothingness. Close to the ending of the main game, Xerneas made the partner "remember" that, in their previous life, they used to be Mew, having fought the Dark Matter alongside the player in the distant past. Due to their past attempt of defeating Dark Matter having actually failed, Mew and the player had agreed to have their memories erased by Mew, all in an attempt to avoid repeating their mistakes in the future. As the partner had accepted Dark Matter, it had disappeared for good, but doing this had also caused the part of Dark Matter that originated from Mew to disappear as well, forcing the partner to leave the Pokémon world after explaining the truth of their past to the player.
Dark Matter has no type, and its size matches that of a gigantic Pokémon. In the first phase of the battle, Dark Matter's core is protected by a cage-like structure. In the second phase, its shell takes on a sphere-like form, which breaks up a bit every time Dark Matter takes enough damage. After being cracked for the first time, Dark Matter takes on a semi-random type, which resists the type of the last move that hit it. Its type will change each time the sphere gets more cracked, which will happen a total of three times during the fight. In case an Alliance is used to do this, one of the moves used as a part of it will be chosen at random, even if one of the moves failed to hit.
- Dark Matter - With this Ability, the text will say "Dark Matter blew away its surroundings!", and Dark Matter will blow back all targets around it, similar to Whirlwind or Roar. This automatically happens in the second phase, when it takes enough damage to crack its shell; this happens three times. This Ability cannot be affected by Ability-changing moves or items, such as the Truant Wand.
Like the Bittercold in Pokémon Mystery Dungeon: Gates to Infinity, Dark Matter also has special attacks that are unique to it. However, they emphasize less on causing negative status effects and more on dealing damage. All of these attacks have 99 PP each, and are 'No type' in the game's code, meaning they are typeless. Unlike the Bittercold, these moves have actual names in the game's code (rather than UNUSED), but the names are still not displayed in-game.
- Charging Start N - Dark Matter charges up its power for five turns, then unleashes countless dark spires across the entire arena. Where it will strike is telegraphed by red tiles that must be avoided in order to prevent the attack from hitting; the player's partner will automatically move to a safe tile. It is only used in its first phase.
- Charging Start F - Almost identical to Charging Start N, with two differences: it takes three turns to charge, and it uses this attack in its second phase.
- Mow Down - Dark Matter rears up a wave of darkness like it would an arm, and then swings the "arm" around itself. Despite its appearance, this attack can only hit Pokémon directly in front of it. Deals roughly 45-65 damage to each Pokémon in the attack radius.
- Shadow Casting - Dark Matter lets its animosity lash out, surrounding a target with its dark aura. This attack will either inflict a random status condition or reduce a random stat on a random target in the whole floor
- WAZA_YOBI_03 - Also known as "taking aim and striking", Dark Matter surrounds its body with its dark aura, then strikes with a shadowy blast. Hits and deals damage to the closest target in the whole floor.
- Dark Matter is similar to Dark Rust, the Bittercold, and the Void Shadows in that they can be fought, but are not Pokémon.
- Unlike the Bittercold, but like Dark Rust, Dark Matter speaks on multiple occasions and appears to be sentient.
- In the English version, Dark Matter's dialogue is typed out with inconsistent and seemingly random capitalization, possibly an allusion to it speaking in numerous voices at once.
- Dark Matter shares both its English name and its Japanese name with Dark Matter from the Kirby series. They are both main antagonists that can control the minds of other characters, and both are dark spherical entities with evil plans.
- Like the Bittercold, Dark Matter is created from the negative emotions of Pokémon. According to Ampharos, it is made up of hate, sadness, and rage.
- After the partner chooses to accept Dark Matter and destroys its core, it can faintly be seen saying "ThANK yOU" in white text as the screen fades to white.