Lay Grandsley is portrayed as mellow, approachable, and easygoing. Unlike many pureblood demons, he does not display arrogance or a sense of superiority and instead treats others with kindness and respect, including hybrids who are often discriminated against within demon society. Though he disagrees with royalist ideology, Lay avoids political involvement, showing little interest in formally joining the Unitarians despite sympathizing with their vision of unity. Misa Iliorogue remarks that his attitude itself embodies the Unitarians’ ideals, as he naturally refrains from discrimination and views all demons equally.

Lay has a deep passion for swordsmanship, a fascination that began in his childhood. His exceptional natural talent allowed him to dominate nearly every opponent, which gradually left him disillusioned and bored with combat. This perspective shifted after meeting Anos Voldigoad, whose overwhelming strength finally pushed him to his limits. For the first time, Lay felt genuine excitement in a duel, reigniting his enthusiasm for battle.

As the reincarnation of the Hero Kanon, Lay retains his predecessor’s ideals and commitment to peace. He continues to seek a permanent end to the Great War between humans and demons and was prepared to sacrifice his own life to bring reconciliation between the races. His willingness to shoulder the role of Avos Dilhevia reflects his determination to protect both Anos and the fragile peace Anos had created, ensuring that humanity’s hatred would not be directed at the true Demon King of Tyranny.

Lay Grandsley is depicted as a tall, handsome young man with shoulder-length white hair and striking blue eyes, giving him a calm yet commanding presence. His appearance sets him apart from many of his peers at the Demon King Academy, reflecting both his heritage and his dignified personality.

His attire is a distinctive variation of the academy’s standard uniform for pureblood demons. Lay wears a long coat in black and red tones, fastened with a black belt around the waist. His badge is displayed prominently on his left shoulder, marking his status as a student. The outfit is completed with black trousers and matching shoes, giving him a refined and martial appearance befitting his title as the Demon Swordmaster.

Lay Grandsley was born into the prestigious Yvesta family, a household renowned for its mastery of magic. However, he was unable to inherit the family’s magical lineage and was subsequently cast out. This was due to the influence of a stronger source, Syrica, upon his own source, as Lay was in fact the reincarnation of the legendary Hero Kanon, who had lived two thousand years earlier.

At the age of five, when his family expected him to die, Lay was taken in by Sheila, a half-demon, half-spirit woman who became his adoptive mother. Her decision to care for him drew the ire of the Yvesta family, forcing Sheila and Lay to relocate to avoid further conflict.

Under Sheila’s guidance, Lay was enrolled in the city’s largest sword dojo. However, he left only three days later after defeating his instructor, demonstrating his extraordinary natural talent. He went on to participate in numerous sword competitions, rarely experiencing defeat. His unrivaled skill earned him the title of Demon Swordmaster, and his reputation eventually led to his recommendation to the Demon King Academy.

During this time, Sheila developed spirit disease and was hospitalized at Lognorth Magic Hospital. While visiting her, Lay confided in her about Anos Voldigoad, the first person to ever make him feel a sense of defeat, marking a turning point in his otherwise unchallenged path as a swordsman.

Lay Grandsley possesses extraordinary magical power, physical ability, and unmatched swordsmanship, making him one of the most formidable demons of his era. According to Anos, his immense magic power is notable because he could perceive Anos’ vast reserves of magic without fear. He was capable of supplying the Anos Fan Union with enough power to sustain Guineth, a massive golem, for an indefinite period of time until their eventual defeat.

Physically, Lay demonstrates strength far exceeding that of most demons, though it is acknowledged to be inferior to Anos’. His power can increase under blessings such as Aske, and during his duel with Avos Dilhevia, the use of Teo Aske elevated his strength to a level equal to hers. His speed is even more impressive, as Anos himself admitted he could barely follow Lay’s movements with his Magic Eyes. Lay could end duels in a single motion, sheathing his sword before opponents even realized he had struck, and was swift enough to decapitate two Elder Demon Emperors before they perceived his presence.

As the reincarnation of Hero Kanon, Lay retains deep mastery of source magic. He possesses the rare ability to maintain seven distinct sources, enabling him to hide his true identity even from Anos’ Magic Eyes. This mastery allowed him to separate six of his sources and fuse them with the Seven Elder Demon Emperors. Once reunited with his sources, he regained the ability to resurrect himself, ensuring survival as long as one of his seven sources remains intact.

Lay’s swordsmanship is the cornerstone of his strength. Recognized as a prodigy, he can wield virtually any blade, including holy swords normally untouchable to demons. He has effortlessly taken up multiple demon swords, proving his worth as their master, and even surpassed their original owners in skill. He adeptly dual-wields holy and demon swords, combining their auras to enhance their destructive force. His precision is unmatched, as seen in his duel against Ydol, where he destroyed his opponent’s demon sword by striking the exact same spot with pinpoint accuracy.

His adaptability makes him even more dangerous. Lay’s skill grows rapidly in combat, allowing him to neutralize the shockwaves of Anos’ strikes and evolve his techniques mid-battle. He can even absorb and replicate the abilities of other swordsmen, demonstrated when he flawlessly reproduced Shin Reglia’s hidden art after witnessing it only once.

Anos Voldigoad
Anos is Lay’s closest friend, and the two formed a strong bond shortly after Lay transferred to the academy. Initially, Anos believed their connection stemmed from Lay’s resemblance to his loyal subordinate Shin Reglia, but he later discovered that Lay was actually the reincarnation of Hero Kanon, fulfilling the promise the two had made to one another two thousand years ago. Their friendship is rooted in mutual respect, as Lay finally found someone who could push him to his limits without restraint. He even told his mother that he was happy to have lost to Anos, since it meant he could fight at full strength against a worthy opponent. Despite his love for Misa, Lay was willing to sacrifice his own life to protect Anos and atone for humanity’s mistakes, further proving the depth of their bond.

Misa Iliorogue
Among all his countless lives and reincarnations, Misa is the only one Lay has ever truly loved. His affection for her blossomed after witnessing her determination to save his adoptive mother, Sheila, even at the cost of her own life. Deeply moved, Lay grew closer to her, eventually gifting Misa a one-shell necklace from Azesion, a traditional token of marriage and reunion among soldiers. Their bond only strengthened after he revealed his identity as Avos Dilhevia, and though Misa was upset that he had kept such a secret from her, she accepted him without bitterness. Their love was reaffirmed in the aftermath of the war, as they shared their feelings openly and promised to face the future together.

Sasha Necron
Lay’s interactions with Sasha are lighthearted and teasing, often highlighting her tsundere nature. When she once accused him of thinking only about swords, he quipped that she only thought about the Demon King, leaving her flustered. Another time, when Sasha commented on his growing closeness with Misa, Lay mischievously suggested she should pursue Anos if she felt jealous. While playful, these exchanges reveal a casual camaraderie between them and Lay’s knack for diffusing tension with humor.

Misha Necron
Lay and Misha share a cordial friendship, though their interactions are limited. One notable moment was during a sparring session against Anos, where Misha created a replacement sword for Lay, showing her support in his training. While their relationship is not deeply explored, their respect for one another underscores the bond between Anos’ closest companions.