Reinhard van Astrea/Relationships

Wilhelm van Astrea
Wilhelm's relationship with his grandson is very tense, likely because Reinhard inherited his wife's power as the sword saint just before she died, making her much weaker than she was at her prime. Nevertheless, Wilhelm did want to fix their relationship after the Hakugei was successfully killed. However, after Reinhard was forced to kill Thearesia's resurrected corpse, Wilhelm asked his grandson if he had any regret doing so. After hearing Reinhard's answer, he begins calling the current Sword Saint by his full name, showing that he sees him now as a stranger rather than his grandson.

Natsuki Subaru
Subaru sees Reinhard as a reliable friend, even bragging to the Witch of Sins that he personally knows the current Sword Saint.

Felt
As a part of Felt's fraction, Reinhard is willing to do everything in his power to make Felt the 42th King of Lugnica.