The Cubi Devil's Free Turns
The Cubi Devil reads as a throwaway. It shouldn’t. Its Charm forces a DC 15 Charisma save, and a failure is not a flavor note. The victim is charmed for 1d6 hours, which in combat rounds is effectively the whole fight and then some. That is not a status effect. That is a stolen ally.
Underestimating the save is the mistake. Tables treat the failed roll as an inconvenience and keep swinging. Meanwhile the Cubi Devil now has a second body under its control, ideally the one carrying the heaviest weapon. Turn economy shifts. You lose your action and gain an enemy’s, in the same instant.
Change Shape compounds it. The Cubi Devil can arrive wearing a familiar face, so the “surprise encounter” is often just a conversation that curdles. Add its flight, which is not merely how it moves but how it stays out of melee reach while it picks off saves. The joke monster wins by attrition and misdirection, not damage.
At the table: When a party member fails the Charisma save, hand that player’s initiative to the GM and make the rest of the group fight their own charmed fighter until the 1d6 hours or the Cubi Devil ends.