@Empty @Onyx Yeah it's possible. The Immortal once showed me some codes but they're outdated now. Here's a small glimpse:
>>> p1active
<<< p1a: [opposing Pokémon]
>>> this.boost(p2active, {atk:6, def:6, spa:6, spe:6});
<<< 0
>>> this.boost({atk:6, def:6, spa:6, spe:6}, p2active);
*The [Pokémon]'s Attack rose drastically!
The [Pokémon]'s Defense rose drastically!
The [Pokémon]'s Sp. Atk rose drastically!
The [Pokémon]'s Speed rose drastically!*
<<< true
Now for that you need to be Global Admin+. It'll raise all the stats of your Pokémon to 4x and the opposing Pokémon wouldn't be able to move for a turn.
Tbh you can increase your stats or summon things like Light Screen and Ingrain among others but making a Pokémon "immune" to a certain move is near to impossible unless you're actually *hacking*.
@Psyduck's Headaches Zacian-Crowned used Behemoth Blade and the Calyrex-Shadow got OHKO'd.