Hephaestos is the god of blacksmithing and metalwork in the divine realm of the anime. He is a male deity who presides over the creation of weapons, armor, and magical items, serving as a top-tier guardian of such crafts. His physical appearance is distinctly that of a dwarfish figure; he is short in stature but possesses a very muscular, solid build, reminiscent of an elderly, seasoned craftsman. This weathered, robust appearance aligns perfectly with his identity as a deity of the forge and fire.

Personality-wise, Hephaestos is characterized by a blunt, straightforward, and somewhat self-indulgent nature. He is not overly formal or dignified in the way some other gods might be; instead, his behavior is quite grounded and materialistic. His most defining trait is an overwhelming fondness for strong alcoholic beverages, particularly spirits from other worlds. This love is so potent that it acts as a summons; the mere scent of a powerful liquor from the human protagonist, Tsuyoshi Mukouda, is enough to cause him to spontaneously appear in the middle of offerings. He approaches his divine duties with a practical, businesslike attitude. When he desires something, he proposes direct transactions, offering his divine protections or powerful artifacts in exchange for goods he wants, primarily high-proof alcohol.

Hephaestos's motivations are refreshingly simple and transparent. While he is a reliable and serious god when it comes to his craftsmanship, his primary driving force in the story is his quest for new and exciting alcohol. He is not particularly concerned with grand cosmic battles or the fate of heroes, but rather with securing a steady supply of exotic drinks. This selfish and materialistic motivation is presented humorously, as he and other gods conspire to ensure the safety of Mukouda, not out of altruism, but because they would lose their supply of otherworldly goods if anything happened to him. To maximize his drinking experience, he forms an alliance with Vahagn, the god of war, and the two combine their offering budgets to procure a wider variety of premium liquors.

Within the story's narrative, Hephaestos serves as a divine benefactor who is activated not by heroic deeds but by culinary offerings. His role is primarily that of a supplier of powerful enhancements in exchange for modern-world goods. He forges a key relationship with Mukouda, built on a comical yet pragmatic bartering system where divine blessings are traded for异世界酒 and other commodities. More significantly, he has a close relationship with Sui, the protagonist's slime familiar. Hephaestos takes a liking to Sui and bestows his blessing upon the creature. This divine favor is what grants Sui the extraordinary ability to forge weapons, tools, and kitchen implements, making the diminutive slime an invaluable asset to the party for creating and upgrading their gear.

Hephaestos does not undergo significant emotional development, as his character is largely static and defined by his consistent greed and love for alcohol. However, his role in the story deepens as he becomes more involved with the protagonist's party. His initial random intervention turns into a predictable partnership, especially alongside Vahagn. The two gods begin to collaborate more actively, not only in sharing their offering budgets but also in combat support. In a notable moment, they work together to bestow a crucial skill upon Mukouda and provide him with a national treasure-level magic item known as the Sacred Seal, a powerful holy artifact specifically designed to combat undead creatures. This shows that while his motivations are self-serving, his contributions are undeniably powerful and essential for the party's survival against stronger foes.