First of all, the words that the author uses hurts my brain especially because he is either using them wrong, or spelling them wrong (Common example is "your" and "you're").
Secondly, the plot that the author uses has already been used and reused and there is absolutely nothing unique about the novel. The character design is poor, turning to an unfeeling human being to a total "weeaboo" (lack of a better term) who can't say anything without sounding completely retarded.
And lastly, the worlds that the story is set in may be accurate, but as I have already mentioned, there are some fan fics out there that is a better version of this one. (I remember reading one months ago where he chose the Naruto world first and has better character development, and proper grammar.
Granted the novel only has about 25 chapters so far so I can't really judge the character design and world background that much but just take this fan fic with a bit of salt and be ready to hurt your brain with so many grammar mistakes and generally turning off your brain because this is only good for passing time.