He is Miriam’s blood-related brother. The Roland family are the successors of the lost automaton technology - the technology to turn humans into automata are part of it.
He is also an associate to Mize Altowirz and has a brother/sister relationship with Agnes Boulange
To save his dying sister, he made used of automaton technology that turns her into an automata. Due to the unusual phenomenon of meteor shower, his sister’s life is once again threatened.
To save her, one of the ways is to use Minette’s core as a replacement.