I read through chapter five. The grammar and vocabulary had few errors and high proficiency. I disliked the author's writing style. It's ambiguous and something akin to a summary writing style. It becomes not so engaging for readers and doesn't grab our attention. I believe the author has little information on Hueco Mundo with regards to 'mentors,' giving 'masks' to hollows, and the power of bonds (friendship) in a survival bloodshed setting. I also believe that the isekai tag is making the overall story worse. For the story, I was hoping to see something similar to a progression story based on the novel title. Overall, I'd give this a 2.6/5.