Yuri Drewes holds the prestigious role of Grand Magus within the Royal Magi Assembly. Adopted into the Marquis Drewes family, he presents mid-length purple hair and sharp purple eyes, typically attired in a loose robe over his mage uniform. Sei Takanashi once likened his striking beauty to someone who "stepped out of a painting."

His core dedication lies in researching magic and magical powers. Outwardly carefree and cheerful, he harbors a distinct internal intensity, pursuing subjects of interest with obsessive focus. He exhibits particular fascination with Sei Takanashi's saintly abilities, routinely testing her limits when she acquires new skills. Sei regards him as both a magic expert and a clear, effective teacher. However, he delegates all administrative duties at the Assembly to Magus Hawke due to his significant weakness in such tasks.

Before Sei's arrival, Yuri possessed the kingdom's highest magic level and MP. He uniquely wields appraisal magic to evaluate individuals and boasts exceptional aptitude, enabling rapid analysis of new magic. He commands all affinities—fire, wind, earth, lightning, ice, and holy magic—with documented spells including Fire Lance, Inferno, Wind Cutter, Ground Spear, Round Spark, Ice Spear, Heal, and Holy Arrow. His Round Spark detonates after a 0.5-second delay, damaging and stunning enemies within a 300-radius area. Inferno unleashes encircling flame bursts around him, dealing immediate damage followed by lingering damage-over-time.

During the saint summoning ritual, an error caused him to accidentally pull an additional individual from another world alongside Sei Takanashi. This incident highlights his intense research focus occasionally overriding precision in critical operations. His relentless pursuit of knowledge, especially regarding Sei's capabilities, defines his interactions.