The problem I see is that I personally dn't find useful to spend a card slot in the deck in order to have a bit cheapper spells
I can actually see how this is useful myself.
I would certainly use these, for instance, to allow a deck to splash steal, deflag, firerstorm, etc. off of a single nova use.
It makes cards that would normally be inaccessible due to cost very viable.
Since 3 quanta is the typical splash threshold (any higher cost is just too tricky to get stable), and you can assume that getting at least 2 of these within a few turns is pretty reasonable, that brings the splash threshold up to 5 for mid game. Probably higher if you only need the spell late game... That opens up a pretty wide range of previously inaccessible spells.
Right now, aether has very poor PC, and no mass CC so I could see adding a few of these, a few novas, and splash in a deflag, thunderstorm, upped steal, etc.
Thus, aether splash 'bow is born.
