Rudiger is a man appearing in his twenties with silver hair and has deep green eyes which give off an endless sort of feeling, who appears to be from Northern Europe.
Rudiger's mannerisms are like an art form to which his body exudes a sense of dignity, giving him strong stateliness. He is highly intelligent, able to discern things almost immediately and give professional advice.
Rudiger is a very kind-hearted man as his shared wish with Dulio Gesualdo for the winning the Rating Game World Tournament, is to stop children from being born with Sacred Gears that will affect them negatively like what happened to his son and many other children dying from possessing a Sacred Gear. Rudiger sees Dulio as the best Angel in his eyes, for what he did for his son and holds a great deal of respect for him.
Rudiger became the Bishop for the Head of the Extra Demon House, Mammon. He was a sorcerer who didn't have any amazing feats until he was reincarnated into a Devil. He was simply a high-level sorcerer when he was a human. He made several achievements and eventually became a high-class Devil. Eventually, he got to the Top 10 of the Rating Games very quickly and this spawned heroic tales of his defeats of stronger teams.
Rudiger had difficulty in making a child, though he finally had a son. His son was born with a Sacred Gear which was killing him. His son's hero was Dulio. He wanted to see Dulio. Rudiger had no connection with Heaven so he mostly gave up on it. He still sent a letter to the Underworld headquarter despite thinking that Dulio won't come. But after a few days, Dulio came to meet his son. His son was happy. Dulio came and visited his son frequently. Even after his son died he visited his grave. After seeing Dulio cry for his son, Rudiger was so moved that he himself couldn't stop crying.
Red Dragon Emperor of the Blazing Truth × White Dragon Emperor of the Morning Star: The True Dragon(s) of the Kuoh AcademyEdit
During the match between Issei's and Dulio's teams, Rudiger was present in the spectator room and discussed with Rias the strategies he thought of Dulio's team to be used against Issei's. Some such as exploiting Xenovia to help Irina which cost her the goal and caused her to berate herself, as well as trapping Issei in a bubble showing a recording of Gabriel in a swimsuit. Just when things were seemingly down for Issei's team, Xenovia wore her Crimson Destruction Dragonar armor, upon witnessing it Rias who gave a bitter smile and questioned if he had predicted this outcome, but Rudiger simply remained silent. The results however was in favor of Dulio's team who won that game.
Powers & AbilitiesEdit
Demonic Power: Rudiger has all the powers and abilities common to Devils, including the power to cast spells.
Immense Strength: As the 7th ranker of the Rating Games and a Reincarnated Devil who has ascended to Ultimate-Class, Rudiger presumably has a great deal of power.
Master Magician: As the founder of Rosenkreutzer, Rudiger is a highly skilled master Magician, being a high level sorcerer during his life as a human. After he was reincarnated into a Devil as a Bishop, Rudiger's magic abilities were greatly enhanced which allowed him to make great achievements and be promoted to an Ultimate-Class Devil.
- Immense Magic Power: As a high level sorcerer and a former Bishop who was promoted into an Ultimate-Class Devil, Rudiger has incredibly strong magic abilities.
Master Strategist: Rudiger is renowned for his incredible strategies with a focus on psychological warfare, earning him the title of "Upsetting Sorcerer". His genius has allowed him to defeat the former Dragon King Tannin and his peerage several times in Rating Game matches despite the great difference in power. At one point, he was almost able to defeat the Emperor Diehauser Belial himself. In Volume 23, during Dulio's Rating Game against Issei, Rudiger developed a strategy that exploited Issei's perverted weakness towards beautiful women, using Dulio's bubble to show Issei a video projection of Gabriel changing into several erotic outfits. Through this plan, Issei was successfully incapacitated for several minutes.
Flight: Being a Devil, Rudiger can fly using his Devil wings.
- Rudiger is one of two Reincarnated Devils to achieve Ultimate-class Devil, along with Tannin.
- Rudiger is a German given name. The meaning comes from Old High German: hruod (fame) and ger (spear).
- Rosenkreutz means "Rose Cross".
- Rosenkreutzer means "Rosy Cross".
- Rosenkreutz, first name Christian, is the legendary, possibly allegorical, founder of the Rosicrucian Order (Order of the Rose Cross) who is a semi-mythical figure.
- His first name along with him being the last supposed descendant of the German family Germelshausen would suggest Rudiger is German.