My Life For Aiur? I Barely Know 'Er! - Lets Play+Read Starcraft 2: Legacy of the Void

[noob]

Indeed, but you need a critical mass for that. Shadow Fury tends to spread its hits out over the maximum number of targets, so if you have, say, a pack of zerglings around a spore crawler, the crawler will only get hit once per DT.

In early missions the critical mass is at something like 4 dts (because the instahit nature means that it does not deal a lot of overkill) but it raises probably over time.