Being X/Relationships

Tanya von Degurechaff
Due to her being Atheist, he reincarnated her as a girl and forced her to become his prophet carrying a relic with a blessing coming from him. His goal is to make her and humanity acknowledge and praise his name as their Creator.

Mary Sue
He is using her as an apostle a.k.a tool for his ambition to make humanity and Tanya accept him as their Creator.