One of the greatest threats to Yusei Fudo and his Yu-Gi-Oh! 5D’s companions were the Dark Signers. This group of antagonistic, vengeful duelists had it out for the Signers. Rex Goodwin, Carliy Carmine, Kalin Kessler, and more challenged the heroes and put up quite a fight! One the techniques that the Dark Signers used against our protagonists was Dark Synchro Summoning. But, what even is this technique? What is a Dark Synchro?

Dragons and Darkness
Anyone familiar with the Yu-Gi-Oh! 5D’s anime series or manga knows about the Signers and their dragons, and their natural enemies, the supernatural Earthbound Immortals. These two groups are at odds with one another, and their feud began long, long ago when the Crimson Dragon sealed the Immortals away within the Nazca Lines. Since then, the Immortals have lent their power to certain individuals to enact their revenge against the dragons and their Signers. And just like the Signers use Synchro Summoning, the Dark Signers use a corrupted method of summoning known as the Dark Synchro.
Synchro vs Synchro
The Dark Signers use a summoning technique called Dark Synchro Summoning. This mechanic only exists in the anime, manga, and Yu-Gi-Oh! Tag Force video games. Some Dark Synchro Monsters are in the TCG/OCG, but they have been modified into Synchro Monsters. So, how does Dark Synchro Summoning work? Well, it’s kind of like regular Synchro Summoning, but with a dark twist.
To perform a Synchro Summon, you need to have a Tuner plus one or more non-Tuners with Levels that add up to the Level of the Synchro Monster. For example: Junk Synchron + Quillbolt Hedgehog = Junk Warrior. Synchro Monsters have the classic white background, but Dark Synchro Monsters have a greyish background. The biggest difference between these two types of cards is that Dark Synchro Monsters have a negative Level, which is represented by blue orbs with purple stars, instead of red orbs with yellow stars. So, how do you even summon a Dark Synchro Monster?
Dark Synchro Summoning

How do you perform a Dark Synchro Summon? Well, it’s almost like Synchro Summoning, but in reverse. First, you need a DARK Tuner. Secondly, you need a non-Tuner. Then, you send both of those to GY to summon a Dark Synchro Monster with a Level that is equal to the Level of the Tuner minus the Level of the non-Tuner. This will give you a negative Level. This type of Synchro Summoning is not currently available in the TCG/OCG, and the closest we are to this is probably Ursartic.
Below are some examples of Dark Synchro Monsters in the anime and manga: