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@Wokolion While it is true that vast (and I do mean vast) majority of characters don't get above planetary, many characters surpass Galaxy AP. Tamamo is stated at numerous points that with all nine tails, she'd be a universal level threat. There's also BB, after she swallowed and became the Moon Cell, who should be capable of whatever the Moon Cell did, such as creating a barrier that can cut through 8 dimensions. In Strange Fake, when Gilgamesh used a Full Power Enuma Elish, it was stated by the narrator that Enkidu was the sole reason that The World wasn't destroyed. This can be lowballed to planetary, more likely it is universal as the Fate series loves using "The World" with reference to the universe, and you could high ball it to 6-Dimensional thanks to The World encompassing Avalon, which exists up to the 6th dimension (so much so that the Five Magics will always fail to bypass Avalon and it is comparable to True Magic). Then there's The Swirl of the Root (aka The Root or Akasha), which is a metaphysical "force" that exists beyond everything else in the entire Nasuverse, transcendent of reality, dualistic function, and all concepts, being the origin and endpoint for all things, and controls and exists at the summit of all dimensional theories. Thus, The Root, and by extension Void Shiki and, at an extreme wank, Manaka should scale to either an extremely high dimensional level or Outerversal. There's also the stupid number of hax in the verse that could just allow the more haxed out characters to hit way higher than they would be able to physically.
TLDR, Gil, Tamamo, BB, and the Root are my arguments for AP being much higher than Galaxy, though even with that: hax could allow them to hit higher. I don't intend to carry this argument any further, so if you disagree, let's agree to disagree cause I don't want this to turn into a shit show in my favourite author's conversation section and we all have lives outside of this.
PS: You're a legend for reading this.