Mob Psycho 100. The customer always leaves satisfied. Reigen is the type of person to think and carefully consider things. In a way he knew that the claw people were bad news - and thusly he went to talk to them - like a responsible adult. He believed he had to be someone that Mob - or people - could look up to. And Shigeo did, he truly did. He made Mob who he is; an altruistic good natured boy. Fast foward (or back, technically) to ep 12 of the anime, we see Mob about to explode. We tend to forget that he's 'just a kid' and that he does have conflicting thoughts. Going 'crazy' to save his friends is a good thing, right? Prioritize the well being of the majority over the minority. Most 'good' people would come to that conclusion. However, such an act is hard, especially for someone as good as Mob. 'killing' (smilie) 1 to save 10 is a good thing, but it would still destroy Mob internally knowing he 'killed' one. Essentially, it's the lesser of two evils. Reigen knew this, and in his ultra altruism, decided to take all that stress and responsibility.  He didn't want Mob, his beloved pupil, or the Claw, to suffer. He took all the responsibility to myself. 'I shall solve this as an adult'. This was an even greater sacrifice as he didn't know Mob's power would be.")