Tar Snare

The -3/-2 split is the whole calculus here, and the asymmetry tells you what this spell was built to do. A flat -3/-3 would be the cleaner number, but trimming a point off the toughness reduction is the lever that separates "answers the small bodies of a slower black-based deck" from "answers anything." The math is unforgiving on the high end: -2 toughness folds a one- or two-toughness creature outright but leaves a three-toughness body alive at one, so the spell is a clean one-for-one only against the smallest end of the curve. The -3 to power is where the rest of the value lives, and it lives in combat. Shrink an attacker before damage and the spell doubles as a one-creature fog; cast it on a blocker and you push through a trade you would otherwise lose. Played at instant speed, it occupies the same window as a combat trick: respond to an attack, eat a pump spell mid-stack, or knock out a freshly summoned blocker before it gets used. As pure removal it is firmly conditional, the kind of -X/-Y line black has printed in dozens of variations to fill out a curve when the format's creatures stay small enough for it to keep pace. The toughness number is the only thing standing between it and obsolescence: against two-toughness bodies it is a tidy one-for-one, and against anything bigger it is a tempo play that buys a turn rather than a permanent answer.