Ok so this series is getting worse and worse, sooo many wasted panels to show walking up to a student or just most movements in general. Him covering for that bully makes literally zero sense and also an entire class saw what happened so I dunno why no-one else said anything.
Towards the end we discover 2 things, somehow no-one can kill monsters anymore (Then society would fall cause a single monster attack would destroy a town) and that now suddenly he wants to be incognito and that he's happy that he's needed this era (I already dislike this MC and it looks like it's not gonna get better).
The whole him being dismissed as the Sage would have been incredibly easy to prove too, just show some magic also we know for a fact people can see magic auras and his aura alone paralyzes people he's so much more powerful then them.....