Mumen Rider is >>>>> tiers. I think Caped Baldy was serious when he was praising him (And frankly, was jealous that for him, being a courageous hero who risks his life actually meant something.)
I have a feeling Blast is Saitama level.
He even talks like Saitama. (It's just a hobby.)
Only question is, whether he in fact is Saitama, under an old name, and he started the hero association and became it's lead member without even realizing it, or whether it's the Captain Marvel to his Superman.