Man the more I think about the notion of EC being remotely comparable to Blast the more I hate it. It's just so insane.
Like even the argument that Blast might've just been weaker at the time makes no sense because 1. He survived a direct encounter with God right after, if EC could damage Blast but God couldn't kill him...anyways 2. Even at the time he was still the number 1 S-Class Hero just because of how strong he was, meaning that by default he was stronger than Tatsumaki. Would that imply that Tatsumaki would struggle greatly to defeat Elder Centipede? And 3. If nothing else he was for sure comparable to a human Empty Void who would still have been stronger than any other ninja and 99% surely would've been stronger than Flashy Flash back then.
Then you get into the legitimate scaling wherein it becomes downright silly. EC being slightly harmed by a moderately pumped up Metal Bat who got somewhat low-diffed by Hero Hunter Garou, moderately harmed by Bang and Bomb though became stronger as a result, and moderately harmed by Genos though regenerated shortly thereafter, not to mention that he lacked the capacity to deal any form of real damage to any of these 4 besides his acid, again, unable to hurt 4 characters with mid-tier S-Class durability at best, but supposedly able to hurt Blast if that damage wasn't done by God which it probably was, and then the fact that Awakening Breath Bang was implied to be able to put up a fight and actually stall him long enough for Bomb and Genos to escape. I mean holy shit. And THEN you have the fact that Sage Centipede is blatantly superior to EC in every way, but got mid-diffed by Perfected Fist Monster Garou, who was incomparably weaker than current Blast.