Like his fellow Holy Knights, Ardbeg harbors a great hate for the Demon Clan which is motivated by the loss of his daughter during the Holy War. Despite being a kind-hearted man, his trauma and depression led him to act in the worst way.
Ardbeg lived in a village that was destroyed by demons during the New Holy War, losing his baby daughter in the incident. He awakened his magic power from the shock of this incident.
Just when he was wandering in despair, Arthur Pendragon appeared before him and offered him to join his cause of creating a world just for humanity and thus bring his daughter back.
After becoming a Holy Knight, Ardbeg settled in Dalflare Range because the Crystal Grotto's crystals were said to be a connection to the Capital of the Dead. However, in five years Ardbeg was never able to contact his daughter.
Ardbeg introduces himself to Anghalhad and Nasiens claiming to be a hunter. He explains to them that the village where Percival and Donny entered is a monster village, since he himself saw that when leaving it the residents become monsters and that no traveler who has been to the village has returned. Anghalhad and Nasiens decide that they must also go to help their companions, so Ardbeg explains that the only way to undo the barrier that surrounds the village is to destroy the idol in the center of the village.
After the idol was destroyed and the villagers revealed themselves as demons, Ardbeg appears revealing himself to be a Holy Knight and locks up all the demons of the village in an Amber of the Four Archangels, despite the Elder trying to explain that the demons of the village are deserters who refused to fight in the Holy War.
Percival attempts to retrieve the Ambar and free his new friends, and Ardbeg identifies him as one of the Four Knights of Apocalypse and attacks him believing him to be a cursed ally of the demons. While Percvial is attacked by Ardbeg's beast, Cernunnos, Anghlahad threatens Ardbeg with her rapier claiming that he does not understand why she did not notice that he was lying to them. Ardbeg claims that he did not lie at any time, since he is a hunter, of demons, and that he sincerely wanted to help their companions because he did not know of Percival's presence. As the two fight, Anghalhad tries to convince him to release the demons, but Ardbeg tells her about the tragedies that the Demon Clan brought to humans during the Holy War.
After Percival and Nasiens defeat Cernunnos, ardbeg flees to the Crystal Grotto, where he manages to evade Percival's group and have enough time to use his magical power, Reverse, to turn them into babies. The "Elder" then appears revealing that he knows the true reasons for his stay at the Grotto, hoping to see his deceased daughter again, the Elder offers to reunite him with her in exchange for him to undo her magic and gave him the Amber. Ardbeg is incredulous at his words and asks how his Reverse didn't affect him. The Elder explains that his magic requires one minute for every year that he rejuvenates, so having it over 3,000 years, it would take about 3,000 minutes to affect him. Arden is shocked by such a statement and demands that I tell him who he really is.
The "Elder" strikes a striking pose and after undoing his magic, he reveals himself as Gowther the Goat's Sin of Lust. After explaining his reasons for helping the demons and recovering the Amber, Gowther asks Ardbeg to stop when he takes Percival and Anghalhad prisoners, but he runs away with them.
Gowther catches up to him, asking for them to speak, but Ardbeg threatens to dive into the void if he gets close. Gowther shows him an illusion of his daughter to convince him not to. Although Ardbeg is able to understand that it is false, the joy invades him to see and feel his daughter again. Although Ardbeg and Gowther manage to reach an understanding, an attack from two magic-infused spears alarms Gowther. He is forced to jump to save Percival from one of them, ending up holding onto the edge of the mountain while Ardbeg sacrifices himself to save Anghalhad.
逆再生, Ribāsu」: Ardbeg's magic power that allows him to revert his opponents to a younger age, reducing them to babies. Reverse works at roughly a rate of one year per minute.
- Like many of the Camelot Holy Knights, Ardbeg is named after the Ardbeg distillery, a Scotch whisky distillery on the south coast of the isle of Islay, Argyll and Bute, Scotland, in the Inner Hebrides group of islands, founded in 1815.