Q: If I play snake attack on creatures that already have double breaker can those creatures break four shields?

Q: If a evolution creature is sent to the mana zone what happens to the creature underneath it?

Q: If I play a shield trigger creature from my shield zone can it attack next turn or block the same turn it is played?

-Does the creature count as two mana or one mana when it is sent to the mana zone?

Like I said above both creatures go to the mana zone and seperate and become single creatures again that can produce 1 mana each.