@Essence: How about this summoning four 3/3 creatures for 10/9?
I am having a hard time seeing the appeal, to be honest. The Rewind synergy requires you to be playing a Rainbow, which is already strapped for
from FFQ/Druid (barring SoR, that is), or that you get really lucky and one of them is a Jade Dragon or something, and in that case you're carrying Rewind "just in case" that scenario comes up.
Frogtal requires a few Aether Towers, but you can summon 5 3/3 creatures (or 5 5/3 creatures) for your proposed cost of 10
.
Yet another completely different idea that just came to me(sorry if you don't like that I'm proposing things in your thread, but I just figured it can't hurt. Ignore it if you like): Something that would convert Skeletons into some other sort of creature (breathing "life" into them). I'm not sure what they would be converted to though. I think it would have to be something humanoid, perhaps introduce some sort of 'Zombie' card. Mummy would work, but bumping a field of 1/1 or 2/2 creatures to 5/3 seems too much.
I think a very interesting idea would be to convert skeletons to FFQ, as it would have Synergy with
but require a ton of quanta to work, which would explain why it needs to drain all remaining
.
Again, I apologize if you feel like I'm hijacking your thread. I really like the idea of having a "Drain all remaining ___" for each element, and am glad you're heading up the effort.