Eternal Dream
Firstly something is wrong with the concept of time travel and the consistency of the present and the past of the mc, it is my assumption that the mc has been shut in his house after he came back to the past, that means he has not caused a butterfly effect, what happened in his past life should also happen presently, here he say he heard about the case in his past life, which to my assumption means that there were other people to tackle that case in his past life, which should have been the same as well presently because he is reliving what has already happened. That is to say without the mc altering the past then he should not have gotten this case because it was not his in the past. Which either means the mc has already caused a butterfly effect which does not make sense, or rather the rules of time travel are being ignored by the author.