Sure the MC is kinda scummy and a little very heartless, and this novel won't be for everyone but I loved it. Don't get me wrong. I enjoy novels like QWTFOTD, I'm Scattering IQ to the Protagonist, HDS, etc. Where the MC knows his lover maintains the same soul life after life and actively searches for him, but I also think that Face Slapping the Slag Gong System is a jewel in how the MC differs from the others. Not reading to the end, one might think MC is promiscuous in that he does end up sleeping with a different guy in each world but surprise surprise! Every single guy that MC sleeps with is a fractured shard of the ML's soul, in essence they are all one guy. MC differs in that he is indifferent to the guys who loves him. He'll love the one who loves him and he'll be faithful but MC never invest any deeper emotions because to him, the worlds weren't real. They were purely tasks he needed to finish so he could go back to his own reality. In all honesty I feel like there isn't much character growth in the MC until the end because he never really reformed from his scummy ways but that might be the MTL. However after learning everything at the end, this novel isn't really about MC slapping the faces of the Slag Gongs, it's more like ML trying to reform the scummy MC and in essence, it sorta worked? I mean, MC does end up wanting to be in a monogamous relationship instead of the initial 10p orgy. My high rating is because in spite of Mc's scumminess (I know it's not a word but it should be) I still liked the story, romance, heartbreak, and everything. It's quite refreshing how one of the personalities (one of my faves) is black bellied enough to try and kill the other eight personalities and only failed because MC went back to those worlds to resolve unfulfilled desires in order to stabilize the fractured shards.
ML made the rules and MC is simply following them. IMO what MC originally tried to do (by making the MLs hate him because MC has no choice but to leave) is a kindness. What is cruel is to return, reverse the hatred and anger back to love, then leave again, making the MLs sad and heartbroken.
to save his lover in RL
later you learn that MC does count his times with all the MLs
Even though the first arc ended up quite sad (I still get sniffles thinking about it)