Dark Synchro Summon

Dark Synchro Summon is the antithesis of a Synchro Summon. Instead of tuning a Tuner Monster with any number of non-Tuner monsters that add up to the selected Synchro Monster's Level, you must use a Dark Tuner Monster with any number of non-Tuner monsters that add up to the selected Dark Synchro Monster. Dark Synchro Monsters are new and unique to the game as they are the only monsters with a Negative Level.