Dragunities have been around for a while. They had a surge of popularity at first, but fell out of use due to the weaknesses they have. But now with Xyz around, they have new potential.
When they first came out, their gameplan was very straightforward, and very predictable. Relying heavily on their field spell, Dragon Ravine, they would effectively turn any and every card in their hand into a Foolish Burial (for Dragons) or Reinforcement of the Army (for level 4 or lower Dragunity monsters).
The favorable play was to summon Dragunity Dux who would then equip to itself Dragunity Phalanx from the Graveyard. Phalanx would then unequip and Special Summon itself to the field. Since it’s a tuner, it would then Synchro with Dux to make Dragunity Knight – Vajrayana. Vajrayana would then equip Phalanx to itself, who would then unequip and Special Summon itself to the field. At this point the player would Synchro Summon a level 8 Synchro monster of their choice, usually Stardust Dragon. This would be followed up with an attack, if it’s not their first turn, some set backrow, and their turn would be over. And they would do this each turn. Use Ravine to search out Dux, then starhop to a level 8 Synchro.
Starhopping is Dux and Phalanx making Vajrayana, then Vajrayana and Phalanx making a level 8 Synchro.
Another route they would take would be to summon Dragunity Legionnaire who would equip Phalanx, who would unequip and Special Summon itself to the field in order to Synchro for a level 5 Monster. T.G. Hyper Librarian being a good choice, because you would net 2 draws every time you starhop to a level 8 Monster. Another common use of Legionnaire was to equip Dragunity Aklys and then use Legionnaire’s effect to unequip it and destroy a face-up monster on the field, with Aklys’s effect activating and destroying another card on the field.
With this being their game plan and more or less their only path to victory, it was very easy to disrupt the deck. A simple D.D. Crow banishing Phalanx from the Graveyard brought them to a grinding halt. An Effect Veiler on Dux stopped them in their tracks. Rivalry of Warlords would make sure they would never Synchro Summon as long as it was around. Being too easy to side against, Dragunities stopped being used. They simply weren’t worth the time. Their gameplan just wasn’t big enough to make its weaknesses worth dealing with.
These weaknesses have stayed with them until even now. Sure, there’s ways of countering them; Imperial Iron Wall, Debunk, backrow hate…But what makes them worth another try is Xyz. Specifically, the Rank 6 Xyz.
Thanks to the ability to easily Synchro 6 and the existence of Dragunity Arma Mystletainn, rank 6 is very accessible to them. The favorable choices being Hieratic Dragon King of Atum and Photon Strike Bounzer.
Because of Atum and Dragunity Knight – Gae Dearg, the deck has several loops available to it. The most prevalent of which are explained in detail here. The best loop at their disposal, however, is this one.
You’ll notice it requires the inclusion of Mist Valley Baby Roc and much use of Dragunity Knight – Gae Dearg. The basic idea is to Synchro Summon Gae Dearg and make Atum to Summon Red-Eyes Darkness Metal Dragon from the Deck. Gae Dearg then functions as a way to get the cards you need from your deck into your hand, Graveyard, or onto your field. REDMD simply keeps bringing Gae Dearg back after he is detached to activate an Xyz Monster’s effect or is used in a Synchro Summon.
There’s a lesser loop that people who don’t have Baby Roc in their deck go for. It starts in the same way as the one linked above, but instead of making Gae Dearg, you make Vajrayana, who puts Phalanx on the field, and you then make Atum who Summons REDMD from the deck, who Summons Vajrayana or Mystletainn from the Graveyard, followed by Synchro Summoning Stardust. The field you are left with (Stardust, Atum, and REDMD with 0 ATK/0 DEF) is much less impressive than that you get with Baby Roc and Gae Dearg in the mix (Stardust, fully powered REDMD, Strike Bounzer, and usually Queen Dragun Djinn as well), but it’s what you’re going to see a lot of due to lack of exposure for the superioir loop.