Not a big fan of the theme here.
You boil water and get a tower?! How does that work?
Originally, it was a spell that for free/one other combined a water and fire pillar into two air ones. But I decided I liked this better.
As to making a tower, it seemed the simplest way to go. I could have had it make a creature "steam" or something, but that would have made it unneeded. When you think about it, how does a
Sapphire pillar create water "quanta"? I mean, the only thing they have in common is blue. What is "quanta", anyway? Come to think of it, why does maxwell's demon kill creatures with a higher attack than defense? How is that a paradox? How the heck does a fire shield hurt a lava golem? It IS on fire itself, right? And what about ...
Yeah. It's a friggin' card game. It doesn't have to make perfect sense.
Anyway, the idea is that when you boil something you create steam, which to me is a part of air. Since you're creating a part of air, you're creating air quanta in a sense. Hence, you're creating a pillar. (As to the new steam card, that makes sense because it RUNS on steam, instead of creating it).
Alternatively, we could just make it boring like the rustler and have it make 2 air per fire.