Magic vs Anti-magic premise. Protagonist has a harem complete with the being "Dense" requirement, he treats them as comrades but the girls treat him as their special one.
Includes tsundere girls, loli who is his weapon, big boobs rabbit girl etc and all of them have a form of traumatic past that in the first few volumes the protagonist will get involved to give them a closure, 1 girl per volume.
Plot wise, protagonist wants to save everyone important to him, he becomes a wielder of an OP weapon with a soul/personality and needs to "level up" but has its fair share of restrictions as well as the normal danger of consuming the wielder if he unleashes full power. He wants to stop a war from breaking out, he believes he is justice incarnate and wants to protect the innocent. Furthermore he wants to create a peaceful world where people of different abilities(magic)/race can co-exist together. He is also against killing, even when it is the enemy, therefore, he gets used by different factions while being dragged around between the respective factions(although he learns of each faction's circumstances, he still believes in world peace) and goes up against the bosses of said faction whom all have agendas entwined with each other.
Also throw in a few "betrayed by one's master/superior" scenario and the "relic of the past manifesting now to finish what has been started long ago" scenario, plus an antagonist who is obsessed with the protagonist as his eternal rival. There is also the usual "protagonist starts out relatively weak in strength and gets stronger and bonds with his weapon" plot as well as him having a special trait that is a double edged sword but allows him to be the wielder of the OP weapon. This results in the "protagonist is the trumph card to change the world" cliche. Fights always end in a "i'm losing badly but this is my final attack, receive my determination" style where he wins in one hit with a sudden overpowered but time limited ability activation to turn the tables after which he faints from exhaustion/wounds but he saved the day.
In other words, it is a very cliche plot. Nothing new, nothing exciting, extremely predictable. Thats not saying it is a bad novel, it is fairly entertaining but it is neither original nor refreshing. I really don't mind the "same shit different title" notion but its biggest flaw is following the shounen stereotypes to the letter. If the cliches i've written here are your preference, then you will enjoy this novel.