The manga had potential for some cool exploration regarding several topics, such as whether you can change the future, how history is written by the victors, or even just some nice political intrigue, but most of it is utterly wasted.
It turns the MC's enemies into mindless, cackling villain caricatures. There are no worthy opponents, their only advantage over him being their status, so, despite the MC supposedly having faced numerous setbacks in the past, it still feels as if I'm reading a wish fulfillment story. Also, the MC's time travel gimmick is only brought up when it's convenient. Really, really disappointing.