Quad decks? Just no. Trio decks hardly work already. I'd be surprised if you don't take Quantum Pillars for a deck with four elements. But really, a deck with four elements is extremely unwise; either go with one or two or go with all of them.
Check out the deck puppy is talking about. By the new definition it is a quad deck. Aaaaaand he says it's working..
The definition says that anything utilizing more than 3 elements is a rainbow deck. This does not mean that it necessarily uses all quanta, or even 4 or more types of quanta. The point is that it uses cards from more than 3 different elements, which makes it a Rainbow type.
Furthermore, adding quad decks means you should add quint decks, and sext decks, and sept decks, and oct decks, and so on until a rainbow deck uses all 12 elements. This is not only unnecessary, it also clogs up the forums and splitting threads about basically the same deck, just because I use a Permafrost shield when you use a Fire Shield.
The definition of decks is given, Rainbows are 4+ different element cards. Remember, these definitions are not only used for making and posting cards, they are also used for tourneys and such, requiring strict adherence to the rules.
I agree, however, that Animate Weapon, Improved Blessing, and such make adhering to the rules hard to do, since Puppy's deck really should be categorized as a trio deck, but that is only basing it on the quanta used. When thinking about this, you have to think differently from games like MtG, where only about .001% of cards have ever been a included in a color without requiring that color in its CC
