>>43191835>>43192670Interestingly Game Freak seemingly wanted us to use Diancie as a mixed attacker because Diancie couldn't learn Power Gem in Gen VI (which makes no sense whatsoever flavor wise, but is not too much of an issue competitively since Diamond Storm is so good) and it can't learn Play Rough, so in Gen 6 you were forced to go mixed with Moonblast/Dazzling Gleam and Diamond Storm. In Gen 7 Diancie can learn Power Gem so you can run a Special STAB set if you really wanted to, again putting aside how great Diamond Storm is. According to the HOME movesets datamine, Diancie will be able to learn Play Rough in Gen 8, so if/when it comes back, you can finally run pure physical STABs.