probably a combination of his great aura control and everyone's bias towards what would normally be the weakest mobYou know, I get that it's probably done for the gags over anything else, but Rimuru is supposed to have a huge aura, right? How come everyone manages to ignore that and assume he's a weakling? Like, even if he somehow isn't leaking ANYTHING the fact that everyone in the room and the five oni in particular are looking to him is kind of a giveaway, innit??
also, it's that trope where the majority of people are idiots and don't pay attention to context, in order to easily set up lots of "protagonist shocks people by being awesome" scenes. It's an obnoxiously overused tropeYou know, I get that it's probably done for the gags over anything else, but Rimuru is supposed to have a huge aura, right? How come everyone manages to ignore that and assume he's a weakling? Like, even if he somehow isn't leaking ANYTHING the fact that everyone in the room and the five oni in particular are looking to him is kind of a giveaway, innit??