Wow this sounds like a great chapter, Al vs Subaru begins.
""I shall begin, Sensei. ―Such that I can be my own self."
Priscilla Barielle was no longer there. Therefore Al― Aldebaran began to act according to his original, once abandoned purpose.
―A battle to remove Natsuki Subaru from this world."
He's trapped Subaru, and might be seeking out his book of the dead to "replace" Subaru. Wow, can't wait for the full translation