If attunement is your ability to "see" your native mana type, and sorcery is just blind manipulation of mana, then if I'm reasonably skilled in sorcery, why can't I attempt to cast spells in my native mana type at 0% attunement? Also, why does attunement matter at all when casting sorcery spells? It's my attunement to my native mana type, not the one I'm trying to manipulate, and plus since I can't see the mana I'm manipulating anyway, it shouldn't matter.

Yes, I know it's this way because of "playability" and all that, just wanted to bring it up.

Attunement is your physiological connection to mana, your nervous system's sensitivity to mana. Bending mana (the fundamental action of casting a spell) is a strenous process and puts stress on your nervous system. When your attunement hits zero, your body is too mana-beaten to bend it further until it rests.

While Attunement is connected to a specific frequency of mana (the mortal brain cannot be hardwired to see more than one type of mana... in nature, anyway), the "mana bar" you draw from to cast spells is not.

-Armifer
"Perinthia's astronomers are faced with a difficult choice. Either they must admit that all their calculations were wrong ... or else they must reveal that the order of the gods is reflected exactly in the city of monsters." - Italo Calvino