Which is a shame because literally everything else is great. The art is memorable, the other characters interesting, the plot hits hard, and the twists are sharp. This would honestly be one of the best manga if not for one massive issue: the main character is a psychopath.
A literal, unable to empathize, willing to let anyone die regardless of how much they like the person, psychopath. He literally kills all hope for any kind of genuine connection to any other character, and thus makes it impossible to connect with the story because the lens we view everything from can't make a connection.
A character just lost everything? There's no time to mourn? Who cares? The MC causes other characters to stop acting like themselves, thus killing all tension, and if that person dies, oh well, I already know every character doesn't matter to the author because no character matters to the main character.
What kind of thought process goes into making a psychopath the main character of any kind of adventure story? Yeah, brilliant move author, you had everything and threw it all away for a character that can't connect to any audience—not even psychopaths, because they don't empathize by their very nature.
And then there's the extremely unrealistic view of what is valuable and what isn't. Sure, getting emotional is stupid, but never being emotional is no better than being a machine. The characters lose what makes them interesting when logic overrides their behavior, and this story wants logic to override all emotions.
Not to mention the extremely toxic, untrue and stupid notion that pure self-centered living and thinking is a good thing. Regularly you see the story try and reward the MC for not thinking of other people, and it's beyond frustrating to read.
If any normal "power of friendship" character was the main character, this story would easily be an 8. If the main character was a normal character without the power of friendship I'd give it a 9. But the main character we get drags this story down to a 3. The awful messaging brings it down to a 1.
Edit: In response to the gaslighting review above mine by ManKum.
I review almost every story I read, and proof can be found in my publicly available list called "Reviewed". Strangely, one has to log into this website to see other users' publically available lists, but I digress. Currently, I have written 151 reviews, only 52 of which are below a 5 star rating.
Edit: This is going into my "unfinished" list as I refuse to continue it.
Furthermore, I read 26 chapters before writing this review. Make of that what you will.
Edit again: luffy4 talks about others reviewing this negatively having a lack of reading comprehension, and then brings up the Joker, Light Yagami, and Jack Horner (the nursery rhyme, I think?) as examples of how those characters don't need to be connected to. I would like to point out they aren't main characters (and for a good reason). Villains don't need the same elements to be liked the way protagonists need them.
The Joker is the embodiment of chaos, and always has something interesting in the works. The main character in this manga is neither chaos nor does he have interesting gags in the works. He's also Batman's foil, and this main character has no batman. If the Joker were to win constantly, he'd suck to read about as the commentary on normal society he normally also embodies would stop working.
Light Yagami has a chance to take out evil all around the world. Who hasn't thought about killing some pedo who did something awful to a child? And that power corrupts him the way it would most people. Also, he had a foil in L. L was so important to Light and the story that, once L died, I stopped watching the show after a few episodes because the show suddenly sucked. Light's heart was in the right place for so long, which is something we can empathize with. Once that was gone, Light was broken, and I hated the character... and so did a lot of others. The main character of this story has no moral foil.
A nursery rhyme that has been criticized for as long as it's existed... or a Shrek villain. So why is he enjoyed? Because he's having fun. Because too many stories nowadays try to redeem villains with a sappy backstory. When someone is having fun, it's easier to empathize with them. Also, Jack's crimes are so cartoonified it prevents him from being someone to hate. Were his crimes r*** and bloody murder, we wouldn't like him so much. He's also defeated. If he won, very few people would cheer. This manga is cheering on the character that sucks the life out of the world. How?
In order for the main character of this manga to be seen as on the good side, everyone else around him must be more evil. It sucks the life out of the world when every villain has to be more evil than your heartless protagonist.
Also, an occasional random act of kindness does not redeem an otherwise heartless character. It sounds like an abused girlfriend defending her abusive boyfriend.