Also, Star Platinum's powerscaling/feats are a bit of a mess right now, at least in terms of its explanation.
Recently he
got downgraded from City Block level AP/Durabilty because the calc that showed it (the fog-inhaling one) had a mistake and when that mistake was fixed it only came out as Building level (despite this, Dio's profile still mentions the calc, which should have been removed). Since Magician's Red was Large Building AP due to a feat it had and Star Platinum is supposed to be superior to it, they scaled Star Platinum's AP to Magician's Red's AP. This is the part I have doubts about (at least in terms of its explanation).
The scaling between SP and MR was partially because MR has a B in power and SP has an A. But these rankings are no longer relevant.
And it was partially because they fought each other so they should logically scale. However, in that fight MR's AP is never really used in a way that SP would scale from. Throughout the fight Avdol never tries to harm or burn SP/Jotaro using his AP. He simply holds Jotaro in place with Red Bind and slowly starts to suffocate him. When SP is summoned he does choke MR, but that would only be comparing SP's AP to MR's durability* and not MR's AP.
(*and MR's durabilty is only Large Building currently because it's supposed to scale to SP's AP, who gets it from scaling with MR's AP which I just showed never did scale)
You could point out that Jotaro was just coming into grips with having a stand and didn't fight his best (that much is true) but that won't change the fact that SP and MR's AP were never scaled direcly. Now, there might be a stand that scales to MR's AP and that SP also scales to, but I'm not too sure. The only other stands Avdol fights is Judgement, who MR curbstomps with ease and doesn't scale to any other stands anyway (unless you count it manhandling Silver Chariot so easily it's not funny), and Silver Chariot.
There might be something in the Silver Chariot fight that scales them but I do remember Polnareff claiming he could stop and deflect MR's fire because his sword can create spaces in air that disperse the flames (which shouldn't make them scale since MR's feat shows us it gets its AP from the sheer heat of its flames and not contact force and Silver Chariot stops/deflects its flames in a way that uses a pushing force and avoids its heat) and when Silver Chariot gets hit square-on, it only survives because it can remove its armour to avoid most burns (with JoJo's crew claiming that Silver Chariot should've been destroyed otherwise).
I think there's definetely some stuff in that fight that could scale them though. If anyone finds it, please mention it.
I should say that the idea of Magician's Red being above all other stands in terms of AP (in Part 3 at least), is not that far fetched. Avdol is confident he can win any fight he ends up in (telling Jotaro he could've used MR's fire to stop SP's attack if it carried on fighting, completely decimating Judgment like it's nothing while acting playful about it etc.) and he's usually a pretty humble guy.
