Rudiger

Rudiger is an archduke candidate from Frenbeltag and currently studying at the Royal Academy.

Rudiger has a strong resemblance to Wilfried - uncanny even in Rozemyne's opinion - though he is taller.

Rudiger seems to hold a grudge toward Rozemyne for reducing her mana-support to his homeduchy upon assuming the rank of High Bishop, which resulted in the already straining duchy falling on even harder times.

When Detlinde invites Wilfried to a tea party and outright rejects Rozemyne's attempts to join too on the argument that she is not Detlinde's true cousin, Rudiger asks if he may join and after a pause Detlinde agrees. His motivation for just stepping between Rozemyne and Detline aren't clear. Since Detlinde was at the time raining ridicule on Rozemyne it is possible he stepped in to protect her, but he did so in a manner that can also be seen as rude and dismissive, especially considering he is from a duchy ranked lower than Ehrenfest.

Spoiler from Part 4 Volume 3 At the tea-party, Rudiger carefully inquired about whether Rozemyne was already engaged with anyone, hinting that Frenbeltag might be seeking to arrange a marriage between the two for political and mana-related reasons, but Wilfried declined to give any information, telling him to leave such questions for the archduke's conference.