Stop me if you've heard this one, a 30+ year old re-incarnates into a child prodigy in a swords and sorcery type medieval world, gets a cheat skill, gets a convenient item that lets them carry infinite junk, and then slowly builds a harem? Now imagine that, only it starts 20 chapters in when the writer apparently decided he didn't like his original idea. He gets to this generic plot by having everyone die in one chapter, all the characters they spent 20+ chapters making important to the MC, just gone, and he gets angry about it for all of 3-4 chapters, and then it becomes that generic story I just described.
Level Up 1. MC's special power is that he can steal stats and abilities. The limitation on it is that he has to be within 6 ft to do so, it's not instant, and he can't steal from corpses. Okay, it's still OP but it's cool that the author put in some reasonable limitations that could add some tension to it's use. Nope, the very first time he accidentally kills an enemy before he can steal it's power, he levels up and now his ability can be used on corpses. Limitations completely destroyed. Range and time and tactical need to keep the opponent alive, gone immediately.
Level Up 2. MC kills a bunch of bandits and gets to their treasure room. He tames a dragon (whom of course is actually a loli), but it turns out she can't speak yet. Ding! MC unlocks two new abilities! You can now speak telepathically with your tamed monsters and slaves. In the same level MC learns generic trope number 1, and unlocks infinite storage... while he conveniently happens to be in the bandits treasure room!