Moves
Wish allows Mega Audino to support its team by keeping their HP up while also healing itself, and Protect prevents Mega Audino from being damaged on the turn that Wish heals it. Protect also allows Mega Audino to scout what move a Choiced foe will lock itself into while reducing the damage of any Z-Moves, such as an All-Out Pummeling from Scrafty. Toxic allows Mega Audino to easily wear down many unboosted attackers in NU, especially combined with Protect. Heal Bell allows Mega Audino to keep its team status free while preventing itself from being worn down by Toxic. Knock Off allows Mega Audino to remove a foe's item, weakening Choiced attackers such as Alolan Exeggutor and Vikavolt and removing items from defensive walls such as Steelix, Golbat and Vaporeon, allowing them to be worn down more easily. Alternatively, Dazzling Gleam lets Mega Audino deal with Guzzlord and prevents it from being setup fodder for Scrafty.
Set Details
Maximum HP investment allows Mega Audino to maximize the healing of its Wishes while also increasing its overall bulk. Maximum Special Defense investment and a Calm nature allow Mega Audino to wall many of NU's special attackers, taking 42% maximum from strong attacks such as Sceptile's Life Orb-boosted Leaf Storm once Mega-Evolved and avoiding a 2HKO from Choice Specs Guzzlord's Sludge Wave. An alternative EV spread of 252 HP / 208 Def / 48 SpA with a Bold nature and Dazzling Gleam as Mega Audino's attacking move allows it to take on physical attackers such as Passimian, Aerodactyl, Scrafty, and Sneasel much more reliably.
Usage Tips
Regenerator should be used to allow Audino to scout which moves dangerous enemy Choiced special attackers such as Heliolisk lock themselves into, as this heavily reduces the risk of a wrong prediction. Afterwards, the user can choose to pivot Audino out again if the foe deals significant damage to it. Thus, Audino should try to avoid Mega Evolving until it needs the additional Fairy typing, for example against Guzzlord or Scrafty. Audino should generally be brought into enemy special attackers such as Guzzlord, Vikavolt, and Magmortar to use its incredible special bulk to keep its team healthy, as well as using Wish to heal up its teammates and Heal Bell when needed.
Team Options
Thanks to its unique ability to check Heliolisk, mixed Mega Abomasnow, Vikavolt, and Choice Specs Whimsicott reliably, Mega Audino can provide excellent role compression to many balance and stall teams in NU. Pokemon that appreciate Wish support such as Steelix, Rhydon, Silvally-Steel, and Hariyama are often great partners to this set, as it can patch up one of their major weaknesses. Seismitoad is a fantastic partner that can comfortably check Steel-types and most Fire-types for Audino as well as set up Stealth Rock. Pokemon that appreciate Mega Audino's ability to check many of the tier's Dark-types such as Rotom and Xatu can make great partners, with Xatu in particular also helping Mega Audino out by checking enemy Steelix and Garbodor and keeping entry hazards away. In general, entry hazard control from Silvally-Steel, Xatu, and Rotom greatly helps Mega Audino out, as otherwise it cannot take advantage of Regenerator to its fullest. If you're using Knock Off, Pokemon that appreciate Steelix having its Leftovers removed such as Klinklang and Braviary can make great partners. If you're using Toxic, Pokemon that appreciate Slowking, Vaporeon, and Cryogonal worn down such as Incineroar, Delphox, and Sneasel are great options. Thanks to Mega Audino's weakness to enemy Poison-types, Pokemon such as Rhydon, Klinklang, and Steelix that can take on the likes of Garbodor are excellent partners. Mega Audino also functions excellently on stall teams, with Pokemon such as Pyukumuku mitigating its weakness to enemy setup sweepers and Pokemon such as Cryogonal removing hazards for it and preventing it from being worn down by repeated switches into enemy Heliolisk. Clerics such as Vaporeon can also help Mega Audino, as if not using Heal Bell itself, it is quite vulnerable to Toxic poison. If using Heal Bell itself, Mega Audino can easily support teammates that are weak to Toxic such as Cryogonal while also supporting any teammates using Rest such as Pyukumuku.