What do you think about the possibility of the existence of a secret association of people on Blast level?
as shown in One Punch-Man Hero Association often overlook the very strong characters so I think that there may be a group of people like Blast who quietly solve dangerous problems.
This could also explain why we have not seen yet magic. :)
and why do they not recruited yet Saitama? maybe they appear only when there is a threat that a person like Blast can not overcome alone. :)