This has been suggested several times, and yes, with a Mark of Entropy, to use one SN per turn it must cause a deficit of 1
per turn.
This, while reasonable, does not remove the fact that you can chain it by simply waiting a few turns (though that is indeed a less effective technique).
I agree that SN is overnerfed. Still, Singularity has been core for several combo, most notably Mutation Sing and Sing OTK.
I agree. Change the cost to 3
. (is this a buff? More like a berf)