From Hidden Arsenal 4 back cover:
Dragunity Knights are the Generals of the Dragunity Army. You can Summon these Synchro Monsters using any Dragon Tuner plus any Winged Beast monster. When you do, your Winged Beast will saddle up and ride into battle on top of your Dragon! Dragunity Knights have high Attack Points and incredible powers. "Dragunity Knight - Trident" can even take Fusion and Synchro Monsters out of your opponent's Extra Deck, before they ever have a chance to use them!