First thing up for consideration is what happens if you use this on a rustler when you have a life mark?
OMG! That's unlimited life quanta!
My best idea is to alter the ability so that it can be only used once per turn.
Yeah, the card should read something like "Target creature's ability cost now costs quanta of your mark. The ability can be used only once per turn".
Do this, and the card is really fine for me!
Also, i was thinking that using this on an enemy creature is (almost) equal to lobotomize it. Really, nice card.
I'd also like to have a mirror card "Desynchronization", sounds like an entropy card. But what Desynchronization should do?
Maybe change the ability randomly?