Gluttony

A homunculus with a bottomless appetite, Gluttony trails after Lust with childlike devotion, whining and clinging when left alone. He speaks in simple bursts, hungry for food and for company, and beneath the harmless, whimpering exterior sits a mouth that can unhinge into something monstrous when provoked.

The show plays a long game with him: he reads as comic relief, a big soft creature who wants only affection and dinner, which makes the reveal of what he's actually capable of land harder. Shiratori's voice work keeps him plaintive and simple even as the character's true nature darkens the joke retroactively.