@Mlemplar plus if I remember correctly in a earlier chapter he said something about corpse explosion stealing his exp I guess cause he isn't personally killing or his summons aren't and he's just using corpses but I don't think he gets all the exp when he kills using corpse explosion and I don't that's true about his summons cause he's been carrying that one girl and she doesn't have summons but she's still leveling up about the same speed as him you have to think this isn't a game but real life for them it wouldn't make sense if they could level up extremely fast and get super strong when there almost barely anyone over level 100 in there world which shows how hard it is to level up