Dark Synchro Monster
Dark Synchro Monsters are a new monster category that will make its debut in Yu-Gi-Oh! 5D's in Episode 27. Dark Synchro Monsters are Synchro Summoned by sending to the Graveyard 1 Dark Tuner Monster and 1 non-Dark Tuner Monster. The non-Dark Tuner Monster's Level minus the Dark Tuner Monster's Level must be equal to the Dark Synchro Monster's Level.
Note that Dark Synchro Monsters and Dark Tuner Monsters are not just DARK Attribute Synchro Monsters, but are a completely different monster category, although they are admittedly similar to Synchro Monsters. Currently, the only know Dark Synchro Monster is "Freezing Fitzgerald".