While testing some things we noticed Multiscale (Ability) is incorrectly reducing the damage of at least 1 (potentially more) direct damage moves.
The one we noticed is "Endeavor".

Gif showing it in action: http://i.imgur.com/w1p81hJ.gif

"Multiscale reduces damage taken from damage-dealing moves by half when at maximum HP. It does not reduce the amount of HP taken from moves that deal direct damage."
Source: https://bulbapedia.bulbagarden.net/wiki ... e_(Ability)

And here is a list of moves that deal direct damage: https://bulbapedia.bulbagarden.net/wiki ... ect_damage

Note:
We did not test every single direct damage move, however, we did test a few. Pain Split seems to be dealing the proper amount of damage. We also tested Stealth Rock and it bypasses Multiscale which, based on some google searching, appears to be the correct functionality.