What's the most super effective attack possible legit?

You know how Shuckle can deal the most damage under legal conditions? This is like that, except with type multipliers instead of damage.

The best I've found so far is 32x damage. On an inverse battle, send out a Smeargle with Skill Swap, Trick-or-Treat and Flying Press against an opponent's Normalize Delcatty, and Skill Swap to get Normalize. Then your opponent should switch to Aggron, which you use Trick-or-Treat on, and then throw it down with the most powerful Flying Press you've ever seen.

Due to Normalize, Flying Press becomes Normal/Flying while Aggron is Steel/Rock/Ghost thanks to Trick-or-Treat. Normal is SE against all three types in inverse battles, and Flying against Rock and Steel, so 2^5=32x damage.

I think this is actually possible without Smeargle, but it would involve Skill juggling so you could get Aggron ToT'd and have Hawlucha/Pikachu Libre with Normalize. On second thought, since neither Aggron nor Hawlucha/Librechu can learn Skill Swap, it would probably be impossible. It might be possible with some Trace trickery though...

Has anyone else got a better legit combo that they can think of? Remember that you can use any battle format!

You can get 32x SE in an Inverse Battle with Flying Press and ToT without using Normalize, but I forgot what combo you need the Pokemon to be.

Under your rules, you are going to NEED to take advantage of Flying Press. Even using ToT/Forest's Curse, you can get at most three type-effectiveness checks, which is at most 8x SE, when using any other move.

32x without Normalize shouldn't be possible, since Fighting and flying share no SEs in either inverse or regular battles. Other type-changing abilities wouldn't work because they only change normal-type moves, and Electrify couldn't work because neither ToT nor Forest's Curse change the opponent into a type that Electric/Flying could hit for SE.