Dark Synchro Monster

A Dark Synchro Monster is an anime and video game-only 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 and Yu-Gi-Oh! 5D's Tag Force 5. 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). They are similar to the new Xyz Monsters: both are colored black and both have their levels/Ranks on the left hand side of the card.

Dark Synchro Monsters are not simply DARK (Attribute) 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 dark grey 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 Kessler's "Hundred-Eyes Dragon" with his "Stardust Dragon". During Crow's duel against Greiger, Greiger used "Darksea Rescue" in the summoning of "Dark Flattop". The anime's version of "Darksea Rescue's" effect not only showed that "Dark Flattop" was a Synchro Monster (and reiterating that all Dark Synchro Monsters 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 Monsters, 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 Monster in the OCG/TCG. All Dark Synchro Monsters have been released as regular Synchro Monsters in the OCG/TCG; their effects have also either been changed and/or modified except "Zeman the Ape King". Although they don't use Dark Tuner Monsters, they still need DARK-Attribute Tuner Monsters, except for "Moon Dragon Quilla", to be Synchro Summoned. Also, they still use the respective Types of the non-Tuner Monsters like in Anime. For e.g. Grady Dark Synchro Summoned Frozen Fitzgerald using Dark Tuner Catastrogue and the Beast-Type Blizzard Lizard.

The Dark Synchro Monster, "Frozen Fitzgerald", was originally supposed to be released in the OCG/TCG within Crimson Crisis as a mentioned Concept Card. This was, however, called off. It is possible the rest of the Dark Synchros were intended to be released, but, were instead released as Synchro Counterparts.

It may be noted that because of the greater difficulty in summoning them, Dark Synchros are generally more powerful than a Synchro of equivalent level.