Fate eggs with mitosis comes to mind.
Well, that's a Trio, and maybe too slow, specially if you have to keep up the
production.
Also, skeletons powering a mitosis bone-dragon farm.
Sounds good, but again, a trio.
Actually, this just goes really, really well with mitosis.
That sounds better.
So a
/
duo with
mark and Mitosis'd Frogs/Dragons comes to mind. But if you have to be worried about keeping up the quanta cost of the Charm, you'll have problems... You'll need Water Pillars/Pendulums to keep it up, and then you'll clog up your deck, and make it too slow. You'll need
for the early-game, so you'll have to add too many
pillars/pends. Not to mention that mitosis is slow...
Actually, the problem behind this card is that it needs a good niche.
Mono-water won't work. Well, it's written in the card.
Any other Mono with water splash won't work. Upkeep.
Balanced duo. You'll need some spawning to make it worth, and
is the only good auto-spawner (Fractal sucks in mono-aether), not to mention you won't be able to add more
creatures, just this.
Going Trio/Quartet is too unstable, and we all know that, but it's the best niche for this card.
Rainbows don't use lots of creatures from the same element, unless you are being based over Fractal (I doubt that). Rainbows also generally don't have a constant
quanta production, as to keep more than 2-3 of this at the same time in the mid-late game (early game, keeping 1 is too much).
Well, I think the upkeep would enlarge the niche to some balanced duos and duos with splash... Maybe it would even be workable in some rainbows...
Just my 2
EDIT:
Maybe we should allow this to affect water too.
Side note: Can we make this the 2nd card in a series of artifacts?
Sounds good, and also solve most of its problems.