It may actually be overpowered. The card cost thing is quite powerful, powerful enough to cost 5 or 6 quanta on its own, I think. Maybe even more.
Then, you have the drain thing. That's gotta cost 2 or 3 quanta, right there.
And then the fact that you can't discard it. 1 extra quanta, just for that.
So that's 9 quanta right there. 7 upgraded, how 'bout?
One thing I'm worried about is it giving Rainbow too much power back. Otherwise, quite an annoying card indeed; it shuts down a Fractal deck.