Gengar

Mega Gengar is the preeminent trapper in Anything Goes and, as such, cannot be ignored when building and playing in the metagame. Its incredible versatility and plethora of utility options give it the unique ability to support essentially all relevant sweepers in the metagame by removing their checks, such as Arceus-Fairy for Zygarde and Marshadow. Its typing and excellent base 130 Speed in tandem with its base 170 Special Attack allow it to eliminate several notable threats, such as non-Choice Scarf Mega Rayquaza, Ultra Necrozma, and Arceus formes. It also has an immunity to Extreme Speed, blocks Rapid Spin, and easily switches into Toxic-reliant walls like Lugia and Skarmory. An immediate offensive presence and a more consistent performance against offense serve to distinguish Mega Gengar from the metagame's other prominent trapper in Gothitelle. A movepool that includes a wide array of utility options allows Mega Gengar to bypass many of its would-be checks. However, its extreme fragility and lack of reliable recovery mean that Mega Gengar can sometimes find difficulty coming into play versus foes like support Arceus formes, Ferrothorn, and Celesteela, is often reliant on prediction, and is much more vulnerable to being Pursuit trapped when compared to Gothitelle. There arises a question of opportunity cost in the use of Mega Gengar, as it prevents one from using other Mega Evolutions such as Mega Rayquaza in particular, and therefore it cannot fit into every build. Lastly, Mega Gengar's prevalence in Anything Goes means that certain otherwise trappable Pokemon sometimes elect to run coverage to handle it, while defensive teams tend to equip their passive walls with Shed Shell or use Pursuit trappers to hinder its effectiveness.