The "I deliberately made my plan stupid so that you would get stronger" shtick really doesn't work in a story like this where the MC was ridiculously overpowered from the very beginning and never actually got stronger by any noticeable metric.
The only 'growth' he's had this entire time was that pathetic "training arc" where he just stared at porn in the hyperbolic time chamber to remember what being a human is like. Besides the fact that he doesn't act any different from before, it doesn't matter because the bad guy only wants to possess his body!