Farigiraf's an absolute beast in doubles Trick Room strategies.
120/70/70 defenses + a solid defensive typing (Normal/Psychic) gives it only two weaknesses and few ways to exploit them. Bug and Dark are fairly relevant offensive typings, but also typings that lack high-damage moves (outside of Megahorn, which no one uses).
Very few Pokemon can remove a Farigiraf from the field without some sort of set-up or assistance. Modest Torkoal using Heat Wave in the sun is a solid 2HKO (100% Eruption just barely manages to get the 1HKO).
While it's on the field, Farigiraf has a crazy amount of support utility. It can outright disable an opponent's Priority moves. It's got access to double screens. It can Helping Hand its ally's moves. It's got Trick Room - turning its own mediocre speed into an advantage and enables entire team strategies. It's also one of the few pokemon with access to Ally Switch.
Offensively, it also has enough threats between access to Foul Play/Low Kick/Grass Knot (which scale based off of opponents) and its base 110 SpAtk + access to Psychic/Psyshock/Future Sight/Hyper Voice STABS + coverage moves like Dazzling Gleam, Energy Ball, Shadow Ball, and Thunderbolt. Base 90 Atk even makes physical choices not completely unviable, with additional access to Earthquake as another option.
A typical moveset for it will almost be guaranteed to include Trick Room and Hyper Voice, but its sheer variety as a potential offensive threat and as a supporter for another offensive mon make it extremely difficult to determine what an opposing Farigiraf is about to do to your own team.
