Overview
Gengar is an offensive powerhouse that can be considered by many the most threatening Pokémon in the April 35 Pokes meta. It has an amazing 130 base SpA stat, that is able to pressure the most bulky walls in the tier with just it's STAB Shadow Ball, while also having an incredible 110 speed stat, allowing it to outspeed the entire meta aside Dugtrio-Alola and Accelgor, who are too frail to ever dare switch in.
Offense
Nasty Plot Gengar with Life Orb is able to sweep through any team that had their checks weakened, dealing insane amounts of damage after a single Nasty Plot to Tinkaton and Tentacruel, while outright OHKOing Cobalion, Drampa, and sometimes even max HP Fezandipiti. Gengar can run Destiny bond to trade with a would be check, encore to allow itself to turn the matchup on Lokix and even substitute to have safer mind games while pain splitting walls with it's low HP stat. It wants to run 29 HP IVs to lose less hp from life orb recoil. Gengar is also often found running Choice Specs to maximize it's damage output, being able to threaten an OHKO on many slower Pokémon while chipping any checks throughout the game. It can also run a choice scarf to outspeed opposing Gengar, Pokémon that run Sand/Slush Rush, and other scarfed Pokémon who are normally used to revenge kill Gengar. This Choiced sets also allow it to use moves like Focus Blast, to defeat opposing Drampa and Stoutland as it tries to switch into Gengar to Pursuit trap it. Giga Drain allows Gengar to regenerate some HP and Psychic Noise to stop Pokémon from healing while hitting Fezandipiti and Tentacruel hard. Many of this sets however choose to run trick, to disrupt the many defensive teams that are common in the meta.
Defense
While Gengar is quite frail, some opt to run a Focus Sash lead set, being able to Taunt opposing leads like Focus Sash Roserade and setting up Toxic Spikes, finishing opposing pokemon with a Destiny Bond. This set can also disrupt through the use of Hypnosis or Will-O-Wisp. Another option is Bulky Gengar, losing investment in it's huge spa stat, to disrupt walls that would normally check it by using Trick with a Black Sludge, getting a Will-O-Wisp and hitting them with a 130 base power ghost STAB move in Hex. Team Options Gengar appreciates any option that can slow pivot, like Alomomola and Slowking, due to how frail it is, only having a 60 HP stat and weak defences in 60/75. Many Spike users like Roserade, Coalossal and Golisopod are highly valuable to help breaking past Tinkaton since many run Leftovers or Assault Vest, and Tentacruel, that usually runs Black Sludge. Gengar also provides the option to spin block for teams that don't rely on Defog Decidueye or Charizard. Additionally, Rabsca can be used to revive Gengar, allowing it to Destiny Bond again or sweep after getting rid of it's check by sacrificing itself.
Counterplay
A lot of checks developed in the meta like Sableye to encore Nasty Plot and live attacks with a maximum Hp and SpDef investment. There are also walls in the form of Tinkaton and Tentacruel that can easily ignore it's stronger Sludge Bomb/Wave and use Knock Off, while receiving wishes from Alomomola. Due to it's frailty, many Scarfed Pokémon can revenge kill it, an example being Stoutland who's able to Pursuit trapping it. Gengar's also susceptible to priority from Lokix's Sucker Punch and Shadow Sneak from Decidueye and Houndstone.
Written by MsousaGamer