Since Skypea size needs to be re-visited, i would like to talk about raigo scaling to OP-verse since imo, is contradictory that enel with ship that uses his own energy has more AP than the whole OP-verse.
Ark maxim fuction according to Viz media.
Basically Ark maxim creates storm clouds, and these storm clouds amplify the volts that Enel put on them.
This is no different from what Nami does, but on a small scale (You need to read the whole chapter)
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It can be seen that a small ball of electricity that only tickled miss doublefinger, but with the storm cloud its energy is amplified and becomes a more powerfuls lightnings capable of hurting miss doublefinger.
So the thunders clouds increases the volts and the amount energy (Thats why that single ball of electricity was able to become multiples lightnings bolts, this is whats happens to enel too, he can just create one lightning bolt at the time)
Let's go back to Enel, as I mentioned, Enel does the same thing as Nami but on a large scale, Ark maxim crates the storm clouds with Enels heat and the water he has inside some machines inside of it
here you can see that enels needs to put volts on the clouds to amplify the amount of volts/energy he used initially, by the storm clouds, here too, and in basically any occasion that enel uses those storms clouds
What's all this about? because Enel says his clouds are going to turn into
dozens (x24 low end) lightningbolts at his biding (binding=adding some volts on the super dense storm clouds)
So basically storm clouds increase the energy/voltage by dozens of times the voltage/energy that Enel initially binded on them.
This makes sense too, because Enel without ark maxim, complety erased bilka, his hometown island.
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I'll just comment this for now, by seeing how you react, i will comment or add other arguments on it.