To begin with, a mea culpa: In looking at the star spawn hulk in the previous post, I skipped over the Psychic Mirror feature. Mentally, I’d noted that it didn’t have any meaningful impact on the hulk’s own tactics—but having noted that to myself, I forgot to say so.
The thing is, Psychic Mirror doesn’t affect anything the hulk does, since the hulk already has another incentive to stand in the midst of its enemies, in the form of Reaping Arms. But Psychic Mirror can affect the behavior of other monsters fighting alongside the hulk. And when you get right down to it, “Psychic Mirror” is an inaccurate name: it should be “Psychic Amplifier,” because for every x points of psychic damage the hulk would take, every creature within 10 feet of it takes x points.
As an example, one commenter mentioned mind flayers, with their Mind Blast action. Suppose an attacking mind flayer blasts five player characters along with a star spawn hulk. First, each of the five player characters makes an Intelligence saving throw. On average, a PC will take 22 points of psychic damage on a failure, 11 on a success. But then the hulk makes its own saving throw, and its Intelligence is a wretched 7, so it has only a 20 percent chance of success—it’s going to fail, and take full damage, four times out of five. But it’s not the one who takes that damage! That damage is passed along to each PC within 10 feet of it—the full amount, even if a PC made his or her own saving throw! (more…)