Gothitelle is undoubtedly one of the best back up mons you can ever have. Capable of eliminating much of OU's threats and walls, Gothitelle must be taken seriously, before you happen to lose your Skarmory or Ferrothorn.
Stallbreaker and wallbreaker
Gothitelle @ Choice Specs
Ability: Shadow Tag
EVs: 252 SAtk / 140 Spd / 116 HP
- Hidden Power [Fire] / Hidden Power [Fighting] / Hidden Power [Ground]
This set is easily one of the metagame's scariest. It has the ability to trap and kill any one of your opponent's threats. Choice Specs is chosen for the damage output, since the Scarf set is pretty slow, and doesn't get enough KO's. However, a Timid Nature is prefered, allowing you to only need 140 Speed EVs to outspeed Mega Venusaur and Rotom-W who run sufficient EVs tou outspeed Max Speed Azumarill. In case you haven't noticed, this set also outspeeds Max Speed Azumarill, allowing you to always hit before a strong Play Rough or Waterfall reaches you.
It is rather important to run this specific spread. You will always hit MVenu before a crippling Sleep Power, hit Rotom-W before a Volt Switch, and force Azumarill into Aqua Jet. An alternate spread of 36 HP / 252 SAtk / 220 Spd and a Modest Nature produces the same Speed result, with more power. However, Gothitelle's ability to take hits will be hugely noticeable. Additionally, you can substitute some SAtk EVs into it's HP stat, since a Modest Nature will keep its damage output higher than a Timid Nature.
As for the set, it is somewhat similar to a gen 5 trapping set. Psyshock allows you to anything weak or neutral to it for tons of damage, specifically Chansey. Psychic can be used an alternative, as it could hit mons who run Bulk Up (Conkeldurr), but the damage output isn't notably different on mons you should use a Psychic STAB on, bar Chansey. Next is Thunderbolt, being one of your best coverage moves. It allows you to take on Dark types (if HP Fighting isnt your HP of choice) and opposing Gothitelle. Next is you Hidden Power of choice. Fire completely destroys Ferrothorn, whereas Fighting has better coverage, and can hit much more, such as Tyranitar and Heatran for big damage. Lastly, if Heatran is a nuisance and myst be eliminated at all costs, running Ground can guarantee a 2HKO all Heatran variants that aren't Air Balloon. Finally, Trick is your stallbreaking move, allowing you to just mess up any Chansey out there, or screw over Assault Vest mons such as Conk or Azumarill.
Dragonite - Dragonite appreciates what Gothitelle can do for it. She eliminates Skarmory and Ferrothorn for it, while Dragonite can rid of Aegislash and Bisharp for her.
Mega Scizor - The Bulky SD set loves Gothitelle support, having her get rid of Skarm and Ferro, as well as crippling common phazers such as Hippowdon, while Scizor cleans up the game after a +2.
Landorus - All Lando sets (bar Rock Polish sets) detest Keldeo. Gothitelle can do a favor for Lando and rid of Keldeo, whom cannot OHKO Gothitelle (even Specs Hydro Pump cant OHKO, granted you are at full HP and rocks are not on the field), allowing you to Psyshock it to oblivion wing. Landorus then is capable of doing a favor for Gothitelle, and eliminating Aegislash, Tyranitar, Heatran, and Bisharp, whome all threaten and/or wall her.
Bisharp - Gothitelle helps beat bulky Steels whom Bisharp has a slight but of trouble beating, as well as beating Mach Punch users and faster fighting types. Once Gothitelle does her job, Bisharp is free to roam the vast playground known as OU.