Hym is an animated Orichalcum lifeform forged by Hadlar using forbidden magic. Initially serving as the Pawn Warrior within Hadlar's Elite Royal Guard, his near-indestructible humanoid form grants immunity to most damage, with only rare methods capable of harming him. He specializes in close-quarters combat, wielding his signature Heat Knuckle technique that channels the Kafrizz fire spell directly into his fists to amplify strikes; his spell usage remains confined to this single attack. Defensively, Hym minimizes damage by adjusting his positioning, a tactic effective even against attacks potent enough to destroy Orichalcum, such as Nova's Northern Granblade.

Early on, Hym displays a cruel, violent, and fiercely loyal personality, especially towards Hadlar, attacking anyone who insults his master. Prideful, hot-headed, and single-minded, he deems only certain opponents like Hyunckel worthy challenges. After their first clash, he develops an intense obsession with defeating Hyunckel, driving actions like a rematch at Vearn's Palace. There, Hyunckel seemingly kills him using the Bloody Scryed technique, impaling him and sending him plummeting from the palace.

Hym survives the fall. Sensing the deaths of Hadlar and his fellow guards triggers his "Promotion," a chess-inspired evolution. This process merges Hadlar's soul, will, and life force with his own, rebirthing him as the Silver-Haired Beast. The metamorphosis alters his appearance, granting long silver hair resembling Hadlar's, and fundamentally shifts his personality. He sheds his vengeful obsession, learns to value the life granted by his fallen comrades' spirits, and forms a bond of mutual respect with Hyunckel, whom he comes to regard as a brother-in-arms.

Reborn as the Silver-Haired Beast, Hym gains access to Light Aura, a life-force energy that enhances his physical capabilities and enables the devastating Aura Knuckle punch. Disgusted by the soulless automatons replacing his former team, he allies with Dai's party, initially seeking revenge against Vearn for betraying Hadlar. He integrates into Chiu's Beast Battalion, gradually respecting Chiu's leadership and revealing a previously unseen lighter, sillier side.

In the final battle against Vearn, Hym's Light Aura proves crucial in countering Mystvearn's abilities and aids Popp in identifying a weakness in Vearn's Demonic Guard of Heaven and Earth technique. Following Vearn's defeat, Hym retires peacefully to Dermline Island alongside Chiu, Crocodine, and Brass, completing his transition from antagonist to redeemed ally.