Some sane people had been telling people to understand the one of the purpose of the flashback. It is to hype the current enemy that the SHs are going to face. The sad part though is that this solidifies Imu as the main villain of this arc which means they wont be the FV. And only BB stocks are going to rise from this.
Not really a fan of the powercreep if Roger, Rocks, Garp, WB, BM and Kaido are not able to damage Imu. It will depend on the panels though if ACoC was used or not type shit. It could also be that Imu cant be harmed unless his real body is damaged in the Pangea castle and hence all damage is recovered from when possessing any subordinate.
But if Imu has no issue dealing with the likes of Roger, Rocks, Garp and WB but he was on his knees and sweating buckets from JB haki blast which was compared to Shanks then that is the biggest Shanks upscale we have. This puts Shanks above the likes of Rocks and Roger.
Feels weird though that Imu was not impressive enough to make Kaido accept him as being able to defeat Kaido but instead waited for JB to come and defeat him.
Sad day for the old gen wankers though who were putting Roger/WB above everyone like Madara/Hashirama.