How about a little throwback action with Demogorgon. Moderately improved, no?

Demogorgon first appeared in Eldritch Wizardry where he is described as having a hypnotic gaze when both of his evil baboon-like heads were fixed upon his enemies. This mesmeric power could affect up to 100 creatures simultaneously, depending on how many hit dice they possessed. Back in those days, hit dice were one of the main factors used to determine the power level of a monster. The more hit dice it had, the more powerful it was.