What if the prophecy of trouble is actually Saitama fighting seriously?

Not sure if the theory has been posted before but I thought I'd share my thoughts. What if the prophesy of the Earth being in trouble isn't actually from any monster threat but actually from Saitama fighting seriously? Likely from a fight with Blast if it turns out he's as strong as One Punch Man himself? I feel like this might fit the tone of the series and makes more sense than some god level monster threat showing up since ultimately any monster strong enough to cause worldwide destruction would be too straightforward for OPM.