Or you're reading wayy too much into it and this is simply setting up Imu's arrival. It wasn't even Imunko that was frozen, it was Imu's damaged shadow lol — how on earth does a shadow with absolutely no physical strength feats not breaking out prove that top-tier powerhouses can't break out? Imu's shadow is weak af, it just relies on hax regen and Domi Reversi, none of which would have any benefit against Loki and Luffy so he's coming back with his real body.
Rn you're applying a no-limit fallacy to Loki's ice — if he tries to freeze Imu's real body and fails then your claim goes out the window.
Amaterasu is actual fire, it's just a higher level of fire... You're reading way too much into all of this lol just take it at face value. This is a fantasy manga where you can kick air to fly and swing swords so strongly that you cut mountains from miles away lmao nothing is functioning as it should 😂 If Loki's ice is magic then everything is magic.
I never said Kuzan couldn't freeze top commanders, I said Kuzan cannot neg-diff top commanders by flash freezing them to refute your claim that Loki could neg-diff Kaido. Kuzan could not neg-diff Jozu — even freezing him in the end was low/mid-diff thanks to Jozu being distracted.
In theory. Remember Oda would never draw Mihawk negging Crocodile, he treats Crocodile with enough respect as if a fight between them would be high diff or something. So when I say Kaidou or Big Mom can get neg diffed I'm not saying Oda would ever draw that because he wouldn't take the disrespect that far.
We can't keep adding caveats and push goal posts every time a feat we don't like takes place. You said let him freeze a top tier, well he used the ability on the Final Villain in wifi mode and instead of the final villain in wifi mode breaking the ice then retreating, the ice was completely uncompromised. It was the same for when Loki defeated Harald. If Imu was pulling these feats off they wouldn't be questioned, it's just the character being given these things doesn't sit right with most.
In One Piece this is as far as you will ever get from Oda, like I said he will never even draw Crocodile get low diffed by Mihawk. We as readers can separate plot from how characters/abilities would interact.
Based on these spoilers I don't have a good enough reason to believe anyone below Gunkimo without a specific counter can break free.