Ferdinand

"I am your Uncle, a servant of the empire, also your only supporter who's in charge of the aftermath work and the communication between spirit witches in different districts"'

- Ferdinand to Sofia/Lilina

Ferdinand is Empire's King brother and uncle of Sofia and Sarah/Samja. He's known as Empire's Spirit Witch contact and his role is to watch her and contact Spirit Witches of others region in case of need. He's aware that Sarah is the Spirit Witch and cover her identity and acts in case of need.

Unaware that Lilina take Sofia's body, he believe that the Lust Queen is the responsible of "Sofia's amnesia" and swear to catch her. So he help Lilina/Sofia to recover memory and lend her his knowledges about Spirit Witches.

Ferdinand go for Torres in order to save the region from a huge monster attack.

He come back later, after the Beast Lady line and discover that Sofia choose Owen as retainer. Since he can't trust this man, he choose to submit Owen to a trial.

Relationship
Empire's King : they are brothers

Feldt : We don't know anything about the relation between them

Elena : We don't know what kind of relations they had...

Sarah/Samja : He is her uncle, we dont know anything more.

Sofia : he know she is the Spirit Witch and helped her by gathering informations, contact other spirit witches and cover her acts.

Lilina : He believe she's guilty for the Archmages murdering and stealing Sofia's memories. He swear to find her and make her pay.