Kuon Aikawa is a high school student possessing genius-level intellect, evidenced by his award-winning research paper presented at an international quantum physics conference. He previously played Vanguard with Suo Yobitsugi before their interactions ceased following an unspecified accident involving Suo.

He has short, messy dark pink hair and typically layers a white long-sleeve shirt underneath a gray short-sleeve shirt, paired with beige slim-fit pants and white slip-on shoes.

Driven by a profound interest in transcending conventional knowledge, Kuon entered the Destined Showdown after Sylbit approached him and confirmed the existence of the planet Cray. His stated wish was to travel to Cray for direct study. His first match in this tournament was against Suo Yobitsugi. During their duel, Kuon pressed Suo about his own wish, revealed his desire to explore Cray, and ultimately defeated him.

Kuon wields a Stoicheia deck centered on "Destined One of Infinity, Levidras." This strategy employs "Infinity Eyes" markers to empower his rear-guards or weaken opponents' units, while enabling attacks from the back row. Later, during the DELUXE tournament, he switched his primary ride deck unit to "Destined King of Infinity, Levidras Empireo" and adopted "Destined One of Supremacy, Lisciafael" as his ace unit. This deck focuses on aggressive multi-attack strategies, leveraging Lisciafael's ability to restand and gain power under specific conditions, such as having no other front row rear-guards, to unleash sequences of consecutive attacks.

In the DELUXE arc, Kuon occasionally reminisced about his past with Suo. Observing Suo's fragmented memories and occasional nostalgic reactions, he deliberately tempered references to their shared history to avoid overwhelming him. His battle record includes victories against Suo during the Destined Showdown and Raika Koshiba in DELUXE, alongside losses to Akina Myodo and Kagetsu Yakumo (off-screen), and an unresolved flashback match against Suo during DELUXE.