Base Swordsmith Tanjiro <= Hantengu & Emotion Clones <<< Demon Slayer Mark Tanjiro (Blitzed Emotion Clones) <<
Dancing Flash Tanjiro (
Stole Zenitsu's bag) <<
Kaigaku <= Base Muichiro & Base Mitsuri <
Gyokko (Objectively stronger than Kaigaku) << Molted Gyokko (Even faster than before) <<< Marked Muichiro (Muichiro blitzed Molted Gyokko) = Marked Mitsuri = Zohakuten (Zohakuten is 4x stronger than the Emotion Clones as a result of combining into one) <<< Literally everyone after the Hashira Training Arc.
We're not done yet.
Post-Hashira Training Tanjiro (At the level of Hashira. Is the bare minimum for all other notable characters) < Post-Hashira Training Mitsuri & Muichiro (The two slowest runners) < Giyu <<< Marked Giyu < Casual Akaza (Blitzed Tanjiro. Wasn't taking his fight against Marked Giyu seriously) <<
Dead Calm Giyu (Giyu's Dead Calm increases his reaction speed) <= Serious Akaza (Outpaced Marked Giyu with his
Final Technique) <<<<
Transparent World Tanjiro (Utterly blitzed Serious Akaza without him being able to do anything about it) <= Post-Decapitation Akaza (was going to get even stronger if he didn't kill himself. Kokushibo said he could've reached greater heights. Doma said that Akaza's growth was something to take note of) <<<< Doma (Akaza could never beat Doma) <<<< Speed Demon Shinobu (Fastest Hashira Doma ever met. Consistently outpaced Doma. Would've blitzed and decapitated Doma if she wasn't weak) << Casual Kokushibo (Objectively stronger than Doma) =
Transparent World Muichiro (dodged Kokushibo's attacks, which previously blitzed him) < Marked Sanemi & Gyomei <<<
Shichishito Blade Form Kokushibo (blitzed the former two) = Marked Gyomei <<<
Monster Form Kokushibo (blitzed Marked Gyomei) <<< 3rd Stage Drugged Muzan's tentacle whips (Muzan is the strongest demon, even when drugged. His whips were consistently outpacing and blitzing the Hashira, which consisted of Gyomei, Mitsuri, Giyu, Obanai, and Sanemi)