This is your goddess, Arcana. She's a goddess who abandoned her name. You both lost your memories and every night since you two met again you've been sharing dreams about the past. Before you met again, she was Ahide's god but you defeated him in combat. She willingly serves and bonds with you now.

I'm manipulating you by making the dreams fake, about us being siblings while you're big brother, in our dreams i'm being pursued by dragons powerless to fight against them while you protect me.