Such a weird thing to lie about. They look like they're pretty close already, so why not just say that you recalled watching your parents die?
No ones going to give you shit for that.
Sooo, he met another reincarnator in the form of fish, only to dismiss him with timeskip. Is there a need for fish reincarnator? Heck, you can replace him with any random but kind passerby and the story wont change.
Someone earlier so called it! I'm not even sure if I want to continue reading this, after all that. While the basic storytelling has been set for ages and so cliches will happen, there's no reason to write it poorly.