If this card is sent from the Monster Card Zone to the Graveyard: You can pay 500 Life Points, then target 1 face-up monster you control; equip this card to that target. If the equipped monster would be destroyed, you can destroy this Equip Card instead.
If you control a Dragunity Knight Vajrayana when Vylon Tetra is sent to the graveyard, you can equip Vylon Tetra to him. Dragunity Knight Vajrayana will be able to use Vylon Tetra as cost to activate his effect.
Usually you can use Vylon Tetra with level-3 or level-4 monsters to Synchro summon level-5 and level-6 monsters respectively. You can also use higher leveled non-tuner monsters but that would be more costly. When used as Synchro material you can equip Vylon Tetra to your Synchro summoned monster for added protection.
Vylon Charger gives your monsters greater boosts the more equips attached to him. Vylon Hept lets you resummon Vylon Tetra for another Synchro summon. Vylon Soldier can change your opponent’s battle position depending on the number equips attached. Vylon Stigma can equip Vylon Tetra to any other monster.