The effect strikes me as green rather than red - and doing it to opponents is something I'd rather not do in volume at all.

I gotta agree with you there. Top-deck manipulation - including that of your opponent - is a notable theme here through it's generally in low amounts where as this going full fatesealing lock. I could see that sort of thing in UB in the vein of Head Games.

I'll just deactive for now until I come up what to do with exactly and in what color.