Lol, I guess I overvalued the impact of the slower speed relative to lockets...
So how about removing the start in opening hand clause and change ability text to:
"N HPs: Fill target's element pool to N at end of turn. Starts ready. N=turn count."
So it costs you health to use and the amount of health used is the amount of quanta it fills the pool to.
As an alternative:
"N-1: Fill target's element pool to N at end of turn. Starts ready. N=turn count."
So that requires the player to spend 1 less quantum than the card will fill the chosen pool to.
That would also mean that it would only be cost effective when used on a pool that has 1 or less quanta in it.
With that effect, this is actually very well suited to entropy or gravity (due to thematic connection with the mathematics)
Multi-Sky Blitz FTW
how so? This card does not produce quanta (i.e. fill the pool) until the end of the turn.