Diseum Von Earlshide rules the Earlshide Kingdom. He bears golden hair, a mustache, and emerald-green eyes, typically dressed in fine clothing radiating charisma and competence, like a capable company president. His personality is relaxed and sociable. He prefers Shin Wolford to call him "Uncle Dis," viewing Shin as a nephew, and maintains informal interactions with Merlin Wolford, discussing personal worries during visits. Diseum values individual ability over noble status and opposes exploiting power for political gain, stipulating that Shin not be used in political warfare upon Magic Academy enrollment. During his student days at the Advanced Magic Academy, Diseum joined the subjugation of the first recorded devil. He saw the army devastated and faced near-certain death before Merlin Wolford and Melida Bowen intervened and defeated the threat. This forged a lasting friendship; Diseum then accompanied them on a vagabond lifestyle where they treated him as an apprentice or "maid" with minimal respect. His decision to abandon his crown prince position during this time caused lingering resentment from his fiancée, Julia. As king, Diseum oversees the Earlshide Kingdom's affairs and advises Shin closely. He recommended Shin's enrollment in the Magic Academy to address a deficiency in common sense resulting from isolation under Merlin's care. His leadership emphasizes practicality and meritocracy. He often mediates between Shin's innovations and the kingdom's stability, cautioning against disruptive magic or technology. His familial relationships include his son, August von Earlshide, who inherits Diseum's traits and relaxed approach to royalty. Diseum's bond with Merlin and Melida remains strong despite past tensions. His dynamic with Shin blends mentorship with familial affection, providing guidance absent from Shin's upbringing.