Dark Synchro Monster

Dark Synchro Monsters are a monster category that debuted in Yu-Gi-Oh! 5D's episode 27 and are also present in Yu-Gi-Oh! 5D's Tag Force 4. they are only in the Absolute Powerforce set for the card game. Dark Synchro Monsters are Dark Synchro Summoned by sending to the Graveyard 1 Dark Tuner monster and 1 non-Tuner monster. Besides the "Dark Tuner Monster", you can use any monster for the Dark Synchro Summon. The non-Tuner Monster's Level minus the Dark Tuner Monster's Level must be equal to the Dark Synchro Monster's Level (note that the Dark Synchro Monsters have a negative level, something that isn't possible with any other monster in the game). Their Levels start at the opposite side of the card (regular cards start at the right side, they start at the left side).

Dark Synchro Monsters are not simply DARK Synchro Monsters, but are a completely different monster category, although they are similar to Synchro Monsters. The color is opposite of a Synchro Monster, with a black card frame.

Dark Synchro monsters function as a subcategory of Synchro Monsters, and are also Synchro Summoned. When Yusei's "Synchro Destructor" dealt damage twice instead of just once because he destroyed Kalin's "One-Hundred Eye Dragon" with his "Stardust Dragon". During Crow's duel against Greiger, Greiger used "Darksea Rescue" in the summoning of "Dark Flat Top". The anime's version of "Darksea Rescue's" effect not only showed that "Dark Flat Top" was a Synchro Monster (and reiterating that all Dark Synchros are Synchro Monsters), but also revealed that Dark Synchro Summoning was a type of Synchro Summoning.

However, as stated above, Dark Synchro Monsters are a subcategory of Synchro Monster, meaning that while a card that involves Synchro Monsters can have an effect on Dark Synchros, they simultaneously act as their own category. This is shown by the Trap Card "Dark Matter", which is activated when a Dark Synchro Monster is destroyed.

There are no Dark Synchro Monsters in the OCG/TCG. However, 4 cards from this category, "Hundred-Eyes Dragon", "Underground Arachnid", "Moon Dragon Quilla", and "Zeman the Ape King", are to be released as regular Synchro Monsters in the OCG. Except for Zeman the Ape King, their effects have also either been changed or modified.