Fantastic Beasts and the Night Keeper

Evicted and desperate, sharp-tongued black-market vet Richard accepts a lucrative job as night keeper at the mysterious Ashford Manor for the noble Catherine. His plan to do nothing and get paid shatters when he saves a dying magical beast, accidentally completing a seal that floods him with immense power. Now mistaken for a legendary hero, he heals more creatures, growing stronger and earning an A-rank badge. But his investigation reveals a horrifying truth: the manor is a crumbling prison holding thousands of calamities, sustained by fourteen ancestral souls. Richard discovers he is the chosen heir, destined to inherit their power and end a century-long nightmare.