We know Whitebeard and Roger liked each other a great deal; after this fight, they were partying like true comrades in arms. So, is their clash here simply smaller? I doubt they were going all out on each other. This obviously isn't their peak...
So, what is? We haven't seen either character go full out in their prime. In Marineford, Newgate couldn't even use his strongest Haki, CoC, due to his health.
IMO, due to the size of Elbaph compared to Egghead, I'd say Joy Boy and Imu's Haki is similar in size (there's a joke in here somewhere). Egghead was smaller, but, honestly, not that much: people complaining about Elbaph's population being small are kind of missing the boat, like someone trying to ride on a Rainbow Bridge without a Svarr. A: Giants are very large, they take us space B: Elbaph isn't that large of an island, they're literally living on the branches of the tree because so much of the lower level is an arctic wasteland) C: Giants fight each other to the death over random ass shit a decent amount, and in general are fierce warriors: they kill each other.
In the end, I think Lilith will use her Island Air Conditioning to help build in the Underworld, and change it's climate.
Anyway, back on track, I think Roger and Newgate were a bit below Joy Boy and Imu. I imagine Oda wants Luffy to surpass Joy Boy/Nika, and everything we've seen indicates the WG never feared Roger the way they do Joy Boy. Like, the WG straight up is TERRIFIED of Nika.
I don't think people realize how broken Gear 5 is: it's literal Rubber Plot Armor that bounces bad luck off of Luffy and back to his opponents. He literally BENDS and STRETCHES reality.
IMO, Luffy is a "good" god of chaos, while Imu is an evil god of order. Luffy's chaos causes order by clearing out old systems, like the Shichibukai, that were corrupt; Imu's order causes chaos by having the world be ripped apart to maintain their specific standards.
Luffy is chaotic, but, not because he's evil, and doesn't care about rules: we can see how polite/earnest Luffy is about following functional societal customs in the HILARIOUS scene where he greets Saul-sama:
Luffy is a force of chaos simply because he prioritizes freedom above everything else. Nika breaks the barriers of what's around him; that's why he and Imu have Island level Haki. Their Haki literally breaks the reality/will of entire islands.
Dressrosa happened IN A DAY, and, sure, there were important events in the days after, but, holy shit: that was an entire revolution, in a SINGLE DAY.
That's why Luffy/Nika is so dangerous. Their Will uplifts and frees everyone around them, and that freedom Luffy gives people in such a slavery/crime focused world is so precious to them, that they're willing to go to war for the man.
Luffy frees people from the worst chains we have: ourselves. Almost every character Luffy interacts with becomes a markedly kinder/better character because of him. Hell, he even briefly fought with Lucci as an ally. LUCCI.
Enel ended up befriending little robot dudes on the moon (after trying and failing to blow them up and blowing up the space pirates too).
Doflamingo is friends with Magellan.
Baby 5 is fucking married.
Imu? Imu controls. Restrains. Even Saturn, one of his closest advisers, is immediately killed after his failure. Even Doflamingo wasn't this evil: Doflamingo would forgive honest failure from his Family, it was only betrayal he had no tolerance for. If you honestly lost/got tricked, Doffy forgave you if you were part of the Family.
Imu takes over his own soldier, and immediately uses her to stab a man trying to save a child through the throat.
Imu is a man-child, a psychopathic, incel simping for women and power he doesn't deserver. Imo this does make Teach arguably more interesting: Teach is evil, but, he's not an incel: he's just plain evil.
Imu is close to Orochi than Kaido or Blackbeard.
People forget Teach was willing to throw hands until Shanks showed up in Marineford: Teach is a legit crazy person.
Imu is sitting in a castle malding over teenage girls hundreds of years younger than him ghosting him and killing their great great great great great grandson over it
Like, we don't talk about that enough. Cobra is Lili's ancestor. Imu killed Cobra... over centuries old simpery.
Imu is like all the worst parts of the Yonkou combined.
EOS Luffy needs to be able to actively subvert power at this level.
This also explains the term "Warrior of Liberation": IMO, Nika/Joy Boy were literally KICKING IMU OUT OF PEOPLE, and returning their smiles and laughter to them.
In Egghead, Dorry and Brogy saved Luffy from the darkness of being vacuum suck throated by Ju Peter the Glizzy Gobbling Throat GOAT of One Piece.
In Elbaph, Luffy will kick the "darkness" of Imu's Demonic Contract out of Dorry and Brogy.
Luffy's Haki should be very strong, and, IMO, since Gunko is being possessed by Imu, rather than Imu himself, Luffy's Haki will be enough to stop Imu here. Possibly with Loki's help.
I do not think Luffy's current Haki is near Roger's, though.
Lastly, the Demonic smiles on the Giants make me wonder if this spell from Imu could have any vague connection to the Science in SMILE Fruits.
