Aegis is a magical set of talking armor that was originally given as a cheat item to one of the people who reincarnated from Japan. His former owner died of sickness, and now Aegis looks for a suitable master.
Aegis is a tall set of silvery white metal armor with no visible joints, though upon closer inspection he is covered in scratches. He is hollow inside but from a distance he's often mistaken for an armored knight. Kazuma notes that Aegis' appearance alone conveys strength and durability.
Aegis is very fond of women, and refuses to be worn by men. He frequently tries to trick women into wearing him, and when they accept he tries to convince them to wear him without any other clothes as well as profess their love to him.
Aegis is aware and proud of his incredible durability, and he often says inappropriate things because he knows he can't be harmed. However, he can feel pain, so he doesn't like defensive style fighters ( and would prefer not to fight at all).
Aegis was worn by a Japanese swordsman years ago and served him him faithfully until the swordsman died of illness. He came as a set with a divine shield who's current whereabouts are unknown.
Eventually he came into the hands of the noble named Undine, a collector of strange treasure who presumable acquired Aegis through illegal methods. Aegis was kept chained in a treasure room. Chris and Kazuma free him to be used against the Demon King's Army, but he refuses to help. He is later captured by Kazuma during the Eris Festival beauty pageant and assists Eris in her escape.
To his dismay, Aegis is given to Mitsurugi Kyouya, who frequently reprimands Aegis for hitting on Cremea and Fio. Aegis runs away to the Crimson Magic Village, allegedly to make Kyouya prove his worthiness against the monsters in the forest. In truth, he goes there because he heard that Crimson Magic Clan women are very attractive. He spends his stay in the village at Nerimaki"s Succubus Lingerie Pub, and later helps Yunyun complete the final trial to become chieftain.
As a piece of armor, Aegis' most notable ability is his incredible durability that borders on indestructibility. He is made of Orichalcum, an extremely valuable material. He is also completely immune to magic.