what if you have more than three aether creatures in play, would all of them be immaterial or only a random three?
All, but only the aether creatures. And there isnt much aether creature that isnt immaterial. And when ball lightning die at the end of turn, say you have 3 ball lightning 1 spider in play, the 3 ball lightning die, the spider will not be immaterial at the end of turn
Don't really like it, really. The only things you can probably use this on are Spiders, Nymphs, Sparks (best choice ever), or mutated aether creatures.
Sparky will need buffing to stay alive, so in a duo deck,this compensate high cost
This also makes aether not just about dragons, while spider will be much better with a high cost, 2hp will still die quickly to things....
Also there is always permenant destruction !