Hector

Hector is a mysterious and powerful figure in Re:Zero − Starting Life in Another World, known as the Warlock of Melancholy (or sometimes referred to as the Devil of Melancholy). He is the bearer of the Authority/Witch Factor of Melancholy, making him a supernumerary "warlock" (the male equivalent to the Witches of Sin) and the only known male associated with that group from 400 years ago.

He appears primarily in flashbacks (notably in Season 2), where he pursues the Witch of Greed, Echidna, to the Sanctuary. There, he easily defeats the original Roswaal L. Mathers and clashes with Echidna herself (the outcome of their battle remains unclear). His actions are the historical reason the Sanctuary barrier was created—to protect against him.

Hector has a gloomy, negative personality that matches his "Melancholy" title, often voicing depressing thoughts. Physically, he's described as a tall, slender young man (appearing around 20) with long, messy charred-brown hair, a stooped posture, unhealthy complexion, and a somewhat androgynous/pretty face.

Very little is known about his full backstory, motives, or current status (he's largely erased from history for unknown reasons), but he ranks among the strongest characters in the series' lore.