Creepy Uncle: The web novel mentions that in his past life, he was
sexually attracted to his underaged niece, and would spend his time masturbating to photos of her. Heck, he even went as far as to place a hidden camera in his niece's bathroom and record her cleaning herself. This aspect of him is removed from the LN, manga, and anime because it was
too creepy even for a
Lovable Sex Maniac protagonist.
False Rape Accusation: After Lilia gets pregnant from her affair with Paul, Zenith was willing to let her travel back to her hometown right after giving birth, despite the bad weather conditions and the fact that the journey would take a month. To save Lilia's life, Rudeus accuses Paul of raping Lilia, even though
Lilia was the one who seduced Paul. This makes Zenith sympathize with Lilia and she agrees to let Lilia stay as part of the family.
Happily Married: He marries Sylphy, Roxy and Eris who all love him deeply and Rudeus loves them just as much in return. He's also a very faithful husband for someone who married three women, refusing to sleep with anyone but his three wives even though they wouldn't mind it.
Lovable Sex Maniac: He does all sort of perverted stuff to his love interests, like stealing their underwear and peeping at them when they're bathing. That never stops the girls from falling in love with him since he has redeeming traits despite his lechery. Even his own younger half-sister, who initially disliked him for being a pervert, ends up adoring him after she sees how cool he is.
Sex for Solace: In the battle against the hydra in the Lapan dungeon, Paul dies protecting Rudeus and although they successfully rescue Zenith, being trapped inside a crystal for years has rendered her to a catatonic state. Grieving his parents' tragedies, Rudeus has sex with Roxy who offered herself to him in an attempt to comfort him, despite knowing he's already married to Sylphy.