Voltanis 1 is used by Dean when you encounter him on the field and your current partner has less than 4 hearts filled, or when Dean is chosen as your partner. Every card is marked as a favorite, so you cannot edit this deck when given the opportunity (once you filled 4 hearts)
Voltanis 2 is used by Dean when you encounter him on the field and your current partner has filled 4 hearts or more.
Voltanis 3 is never used in the Story Mode. Its recipe is given along his other 2 decks once you complete the Story Mode with him as a partner. The only difference with Voltanis 2 is the replacement of Heavy Storm by Harpie's Feather Duster. This recipe's Lv. is unknown because it isn't even available when dueling Dean in Free Duel.
In Yu-Gi-Oh! 5D's Tag Force 5, Dean has two types of Decks. The first is called "Enthusiastic Generation" (熱中時代, Necchuu Jidai). The second is called "Diablo SA" (ディアブロＳＡ, Diaboro SA), referring to the army of Duelbots, called Diablo.