Luke Notos Greyrat
Luke was born into the Notos Greyrat family as an Asura Kingdom high noble. He was tasked at a very young age of being the Guardian Knight to second princess Ariel Anemoi Asura alongside Derrick Redbat. He is very fervent in his duties as a guardian despite his frivolous attitude towards girls and his mediocre skills. Spoiler Luke is indirectly responsible for curing Rudeus' erectile dysfunction by giving one of his aphrodisiacs to Sylphiette. Spoiler He was Hitogami's apostle in stopping Rudeus from supposedly using Ariel for his own personal gains. However, he was able to resist Hitogami's words in the end. Spoiler In the original timeline where Rudeus does not exist, he marries Eris and they become a happy couple together. (Source: Mushoku Tensei Wikia)