Oda is hyping Imu with a complexity of a 5 years old would.
What Imu did in fact? He is effective I can't deny that. In a 9 page chapter he saved all his nakamas including one frozen by an ice that shouldn't be melted that lasted what? 2 chapters? How can we validate Loki words like that?
And then what about reactions? We surely have people commenting about him being stronger than fodders Knights but no reaction beats this
Yeah Kizaru landing on Egghead had way more weight than Imu on Elbaph or even Gorosei on Egghead.
Now let's address the elephant in the room. I know that narratively there is a tendency to think that later villains and introductions characters aside from protagonists will always be stronger. But being by Oda incompetence or the way he wants to tell the story he shows otherwise.
Narratively would make sense for Imu to be top of the verse. But what happened? Kizaru seems to be more dangerous.