The problem with the hybrid mana on 'Avira' is not it existence per se, but the fact that you can't actually add to your mana pool. is a cost that can be paid with one green or white mana, not an actual type of mana. Plus, the art was pulled from deviantart.
Closed.
Edit: I'm not actually sure whether it originally came from deviantart or elsewhere. Regardless, if you plug the image into Google search by image, you'll see that it's been around for a while.
(by enough I'm refering to the pics of the gameday promos with hybrid mana here: http://forums.mtgsalvation.com/showthread.php?t=440699 )
Closed.
Edit: I'm not actually sure whether it originally came from deviantart or elsewhere. Regardless, if you plug the image into Google search by image, you'll see that it's been around for a while.