Abuelo Blass, also known as Brass, is a character from the anime and manga Dragon Quest: Dai no Daibōken. He is a monster magician and the adoptive grandfather of the series' protagonist, Dai. His background is marked by a significant transformation. Originally, he was a high-ranking general in the Dark Army serving under the demon lord Hadlar, where he held the crucial responsibility of training other monsters on Dermline Island. Following Hadlar's defeat, the dark influence over monsters was lifted, and Blass chose to live in peace. He settled on Dermline Island, becoming an unofficial leader who fostered harmony among the various monsters residing there.

Blass is defined by a wise, peace-loving, and deeply caring personality. Despite being a monster, he champions the cause of human-monster harmony and is fluent in human language, greeting visitors amicably. His most defining characteristic is his role as a grandfather to Dai. After discovering the infant Dai, marked with a D, on a shipwreck, Blass took him in and raised him with genuine affection. He is strict yet loving, often clashing with Dai's ambitious dream of becoming a hero as he prioritizes the boy's safety. However, this gentle nature has a dark counterpoint; when subjected to dark magic or mind control, Blass can become destructive and sadistic while retaining his intelligence, as seen when he is brainwashed by the general Crocodine.

In the story, Blass serves as a foundational mentor and guardian for Dai during his childhood on Dermline Island. He attempts to teach Dai magic, though the boy struggles and prefers physical heroics. His role as Dai's primary instructor diminishes with the arrival of the legendary hero Avan. However, Blass remains a crucial supporting figure. He is drawn back into the conflict when Crocodine invades Romos and uses dark magic to brainwash him into fighting against Dai. After being freed from this control by Dai's friend Popp, Blass continues to aid the heroes, notably by retrieving the Crown of Champions, a key item used to forge Dai's powerful sword.

Key relationships define Blass's place in the world. His most important bond is with Dai, whom he loves as a grandson and seeks to protect above all else. He also shares a connection with other residents of Dermline Island, including the golden slime Gome, Dai's first friend. His past as a general under Hadlar establishes former ties with other villains, but his redemption allows him to become an ally to the heroes, including Popp, who plays a key role in breaking the mind control placed upon him.

Throughout the series, Blass demonstrates notable development from a former servant of evil to a benevolent guardian and supportive ally. His character arc highlights the theme of redemption and the possibility of peace between humans and monsters. His abilities are rooted in magic, reflecting his identity as a lump shaman. He is proficient in various offensive spells, including Frizz, Frizzle, Swoosh, and Boom, as well as support magic like Midheal for healing, Squelch to cure poison, and Fuddle to confuse enemies. While his healing magic is noted as less potent than that of the heroine Maam, Blass is a capable fighter despite his age, able to engage in physical combat and wield a rod. His physical appearance is distinctive, with light blue skin, a large tail, and a rod, diverging from the typical red coloration of other lump shamans.