Moves
Knock Off is primarily used for removing items, allowing Mega Banette to cripple bulky walls and hit most Pokemon neutrally. Knock Off is also important as an offensive move on Mega Banette, hitting Ghost- and Psychic-types super effectively. Will-O-Wisp is used in conjunction with Prankster to cripple physical attackers and bulky Pokemon. Shadow Claw is used to hit opposing Ghost- and Psychic-types for more damage than Knock Off while also hitting Mega Evolutions, such as Mega Glalie and Mega Camerupt, and Pokemon with their items Knocked Off. Shadow Claw's main targets consist of physically defensive Slowking and Jellicent, as well as bulky Steel-types such as Escavalier and Steelix. Shadow Sneak is a STAB priority move that circumvents Mega Banette's lacking Speed tier. Shadow Sneak is usually preferred over Sucker Punch because it hits Fighting-types, such as Virizion, neutrally. It is also effective against Pokemon like Delphox, Hoopa, Medicham, and Sigilyph. Sucker Punch can be used over Shadow Sneak to hit Meloetta, as well as potentially OHKO Delphox and Sigilyph. Destiny Bond is an alternative move to stop opposing Pokemon from sweeping, or for securing a KO with a weakened Mega Banette. Finally, Gunk Shot can be used to hit Fairy- and Grass-types super effectively. It most notably hits Pokemon such as Virizion, Granbull, and Mega Audino, but it has a chance of missing and low PP.
Set Details
Banettite is used to Mega Evolve to gain Prankster and enhanced stats. Insomnia is preferred prior to Mega Evolution to ensure Banette is unaffected by Yawn Uxie and Sleep Powder Venusaur. However, Frisk can be used to scout for items held by opposing Pokemon. 252 Attack EVs with an Adamant nature are used to maximize Banette's damage output. 28 Speed EVs allow Banette to outspeed 44 Speed Jellicent prior to Mega Evolution, as well as outspeed Blastoise after Mega Evolution to mitigate the fear of Scald burns. The rest of the EVs are dumped into HP to maximize bulk. An alternative set of 252 Atk / 56 Def / 200 Spe can be used to allow Mega Banette to outspeed Exploud, Emboar, and Abomasnow. This spread also allows Mega Banette to defeat Fletchinder, as Mega Banette will outspeed it and be able to use Destiny Bond before Fletchinder can use Acrobatics.
Usage Tips
Banette should not Mega Evolve if it is possible that Pokemon such as Uxie will try to put it to sleep, as Insomnia can be helpful. In other cases, Mega Evolution should be a top priority. Try to Mega Evolve on slower Pokemon or Pokemon that Banette can afford to take damage from. In other cases, it can be useful to Mega Evolve while using Shadow Sneak or Sucker Punch to not take damage. Try to avoid staying in on Pokemon that can inflict status ailments, as paralysis, burn, and poison are all troubling for Mega Banette. Aim to use a combination of Knock Off and Will-O-Wisp when the opponent switches in a wall such as Alomomola, Aromatisse, or Registeel to remove their means of passive recovery. Shadow Claw can be used to pressure bulky Pokemon even further after their item has been Knocked Off and they have been burned. Will-O-Wisp should be used against physical attackers such as Flygon, Aerodactyl, Rhyperior, and Escavalier. Destiny Bond is hard for setup sweepers to work around, as Mega Banette can easily alternate between an attack and priority Destiny Bond to create mind games for the opponent. Be wary of Lum Berry Drapion, as it can absorb a Will-O-Wisp and Knock Off.
Team Options
Wallbreakers such as Meloetta, Exploud, and Emboar are helpful in allowing Banette to clean late-game, as they can whittle down the majority of bulky walls on the opposing team. Fighting- and Fairy-type partners such as Virizion, Medicham, Sawk, Granbull, and Diancie that can deal with opposing Dark-types for Mega Banette are also appreciated. Furthermore, specially defensive walls such as Diancie and Registeel are useful, as specially offensive Pokemon can take advantage of Banette's mediocre bulk because it can't cripple them with Will-O-Wisp. Since Banette is a Ghost-type, it can spinblock decently and also appreciates entry hazard stacking due to the residual damage entry hazards provide; therefore, Garbodor and Qwilfish make for good teammates. Finally, Banette can benefit from having setup sweeper partners such as Fletchinder and Scrafty, and it can ease setup for them by crippling physical attackers with Will-O-Wisp.