The fact of the matter is that Sandrovich did not emphasize in any way that these were really earthquakes. Frightened birds and strokes indicate only that there was a crash and shock wave. It would be very strange if the characters commented on the usual shock waves, but did not comment on the earthquake, which is tens or hundreds of times greater than anything they have seen before.
Again shockwaves and earthquake calculations use the same type of formula here. You seem to have an issue with how we calculate shockwaves here as opposed to the Kengan feat in particular. So I'd suggest making a CRT for the shockwave and earthquake formula if you truly have issues with this feat in particular. All Ohma's feat is doing is using the shockwave formula which is based upon our earthquake formula so you'd need to make a site wide revision for that.
Moreover, so far this is the only level 7 feat that looks like a blowout and creates too much spread between characters. Karo had parity with Saw Paing,
Karo and Saw don't scale to Ohma.
who in turn could defeat Rey with his brute strength, and Rey caused a lot of inconvenience to Kuroki.
This is blatantly ignoring context Rei was amped by Reno tremendously.
Likewise, Kaneda does his best to break the face of Himuro, who has shown the ability to block Ryu's attacks, who could harm Naidan, who is directly compared to Wakatsuki.
Kaneda nor Himuro ever fought against Naidan. Ryuki could only harm Naidan when going into his bloodlust mode, and Naidan isn't never stated to be comparable to Wakatsuki. Naidan was getting dropped by Liu's Fa Jin's to which Nitoku was tanking left, Nitoku being the same fighter who's rusty and got stomped by a Pre KAT Kanoh. Ryo blocked one attack from a non blood listed Ryuki so again context matters here greatly.
This is a very sloppy scaling, but it shows that the difference between the characters' powers can be 10-20 times, but definitely not thousands.
It's sloppy to you because you have a genuine misunderstanding of the verse with all due respect. You just tried to insinuate that Himuro and Kaneda scale to Naidan since Ryo blocked one attack from a non bloodlusted Ryuki whenever Naidan was stomping Ryuki before the latter went into his killing mode.
Regarding Liu Deng Chen. Lolong himself said that he sees his equal opponent.
Lolong never stated that he sees Liu as an equal opponent, you're thinking of Jurota. The only character in Purgatory who's comparable to Donarie is Arashiyama, as they're the two King's of Purgatory. Liu is not in that roster. Lolong said that Liu's has one of the best martial arts he's seen, not that he considers him as an equal in terms of might. So again, this is misunderstanding and or lack of proper context of the statements. Liu's entire shtick is to attack vitals and inards with his Fa Jin, not his physical strength. Lolong is the same person who's on top of Purgatory and effortlessly stopped a bloodlusted Akoya and Nicholas.
In addition, he was able to defeat Nitoku, who was stronger than the earlier one.
Nitoku during Purgatory wasn't stronger than the time he fought against Kanoh. He stopped fighting and training for years and picked up writing instead. That's literally one of the major reason's why he lost to Liu was because he stopped fighting and pursued writing.
who was able to push the Kano of the Asura times to the limit.
This is actually retconed as we see the actual result of Kanoh vs Nitoku with Kanoh barely damaged while Nitoku was bloodied up and with a broken arm. I fail to see why you didn't mention this.
It definitely cannot be called much weaker than Ohma.
He most certainly can. Even KAT Ohma was fighting against vastly stronger opponents such as Wakatsuki, Kure Raian and Gensai. Ohma was also very cleary much stronger than Liu as he Redirectied Liu's blow where he was hell bent on actually killing Ryuki right then and there.
TLDR; Your arguments rely on personal gripes with how we calculate things on the wiki, are based upon massive misconceptions and fail to provide proper context to which I assume is to lure people into agreeing with you while not providing the full scope.