Granted, Entropy 4 can just give someone a disease, so Jesse is overcomplicating the matter and I really don't think this oculd be anything but Vulgar Magic, but....
I love the magic system in Genesys, with just basic spells (attack, heal, augment, curse, etc), some varying effects with suggested flavor (e.g. "Ice" adds ensnare to an attack, but mechanically it doesn't matter if it is vines, goop, whatever), and how much that effect increases spell difficulty. It lets the players go into a brainstorming session trying to come up with a spell to get out of a very specific situation, and having the game support almost anything.
E.g. this create water idea could be an attack spell with the poisonous quality (making it a hard check), which requires the target to make a hard resilience check or take a bunch of extra damage and strain, which for a skilled mage against a non-boss creature (e.g. an overly ambitious bandit) is well within one-shot range. If they pass the check, they would still take damage from the attack, but would be able to cough up most of the water before it got too serious.
This system sounds very cool also, and I have recently heard of Mage in another thread. I would like to play a system that gives players the ability to come up with spells that the GM doesn't know ahead of time (I seriously dislike long lists of predefined spells), but also has a little more of that hard magic-science set of rules to satisfy my inner Sanderson fanboy. I have built in some external scaffolding around the magic in my Genesys setting that does this, and it has been a ton of fun so far.
My main gripe is that I wish I had more time to play RPGs (more than a couple sessions a month) so I could try out more systems.