Moves
Clanging Scales serves as Kommo-o's main STAB attack, OHKOing Pokemon such as Greninja and Zygarde while also 2HKOing Pokemon such as offensive Mega Gyarados and Mega Venusaur. Its corresponding Z-Move, Clangorous Soulblaze, also boosts all of Kommo-o's stats by one stage, giving it not only the bulk to tank moves such as Never-Ending Nightmare from Aegislash and Tectonic Rage followed by Ice Shard from Donphan, but also the Speed necessary to outspeed base 100 Speed Pokemon such as Mega Charizard Y, Genesect, and Meloetta. Clanging Scales and Clangorous Soulblaze are both sound-based moves, allowing them to bypass Substitutes from Pokemon such as Jumpluff and Flail Mega Lopunny. Close Combat allows Kommo-o to take on Steel-types like Heatran, Magnezone, and Mega Aggron that resist its Dragon-type attacks. It can also more effectively deal with specially defensive Pokemon such as Mega Tyranitar, Chansey, Blissey, and Meloetta, all of which could be issues for Kommo-o if they are allowed to set up or stall. Unfortunately, Close Combat's Defense drops mean it shouldn't be spammed it in matchups against Pokemon like Mega Aggron and Meloetta, where sufficient bulk is important. Flamethrower allows Kommo-o to beat Pokemon such as Genesect, Scizor, stall Tapu Bulu, and Aegislash. It also helps damage Volcarona without activating Swarm, as well as avoid stat drops from Close Combat and Clanging Scales against Pokemon such as Mega Aggron, Volcarona, and Meloetta. Taunt shuts down several stall Pokemon such as Celesteela, Pyukumuku, Chansey, and Blissey, as well as preventing Aegislash from using King's Shield to enter its Shield forme or Metal Sound or Laser Focus to bypass Kommo-o's Special Defense.
Set Details
240 HP and 100 Special Defense EVs with a Calm nature are used to ensure Kommo-o survives a Choice Specs Greninja's Ice Beam and other powerful special attacks like Choice Scarf Porygon-Z's Hyper Beam, Choice Specs Genesect's Ice Beam, and Mega Charizard Y's Air Slash. The 240 HP EVs maximize Kommo-o's physical bulk, letting it tank Zen Headbutt from Adamant Choice Band Victini, Outrage from an offensive Mega Gyarados, and Fake Out followed by Giga Impact from an Adamant Mega Lopunny relatively comfortably. 28 Attack EVs guarantee that Kommo-o's Close Combat is able to OHKO standard Mega Lopunny, even with a Calm nature. 56 EVs in Speed allow Kommo-o to reach 330 Speed after a Clangorous Soulblaze, letting it outspeed and defeat Pokemon such as Mega Charizard Y and Choice Band Victini. The remaining EVs are put into Special Attack, allowing Kommo-o to OHKO Greninja with Clangorous Soulblaze. Both Soundproof and Overcoat can be run on Kommo-o, as each ability has its own niche. Soundproof ensures Kommo-o doesn't always lose to Ditto, opposing Kommo-o, and avoids an unreliable matchup against Metal Sound Aegislash. Overcoat allows Kommo-o to beat a Transformed Smeargle with Clangorous Soulblaze, as a Transformed Smeargle with Soundproof would be immune to it, along with beating non-Flyinium Vivillon as well.
Kommo-o can run a faster, less bulky variant with 88 HP / 28 Atk / 4 Def / 136 SpA / 252 Spe EVs and a Timid nature in order to outspeed and beat bulky Mega Charizard X and Modest Breakneck Blitz Porygon-Z, both of which are threats to standard Kommo-o, while still being able to beat Mega Lopunny and Mega Gyarados. However, with this set it loses to virtually every special attacker it can beat with the standard set, and thus this set should only be run as a niche anti-meta option with very supportive teammates. Additionally, a more offensive EV spread of 128 HP / 252 SpA / 128 Spe can be run in order to have a better matchup against bulky Meta Metagross, and faster threats like offensive Mega Lucario.
Usage Tips
Against bulky special attackers such as Meloetta and Volcarona, Kommo-o should use Clanging Scales and Flamethrower in order to get them in range of Close Combat, as they both have ways to raise their Special Defense but not their Defense. Avoid sending Kommo-o in against any Fairy- and Dragon-type Pokemon, as it cannot deal with any of them except stall Tapu Bulu and Zygarde. Soundproof Kommo-o can consistently beat Metal Sound Aegislash through the following steps. On turn one, Kommo-o should use Clangorous Soulblaze to boost its defenses before Aegislash attacks; this is essential in avoiding significant damage from Aegislash's Z-Move. Then, Kommo-o should use Taunt to disable King's Shield and then KO Aegislash with Flamethrower. This strategy guarantees that Kommo-o always beats Aegislash, as +1 Kommo-o survives Aegislash's Z-Move followed by Shadow Ball and Shadow Sneak. Overcoat Kommo-o will unfortunately have to predict whether or not it uses Metal Sound or attacks, making this variant less reliable.
Team Options
Kommo-o is generally weak against Fairy-, Ice-, Psychic-, Flying-, and Dragon-type Pokemon; naturally bulky Steel-types such as Magearna, Heatran, Aegislash, and Mega Metagross can all provide an excellent defensive backbone against most threats of the aforementioned types, such as Mega Altaria, Kyurem, and Vivillon. Kommo-o can also cover the weaknesses possessed by Steel-types by reliably beating most Ground-, Fire-, and Fighting-types, such as Sturdy Pokemon, Zygarde, Heatran, and standard Mega Lopunny. Alongside the Steel-types, run options in order to cover up a few matchups that Steel-types don't universally cover, such as against Mega Charizard X, Supersonic Skystrike Landorus-T, Dragonite, and Naganadel. Mega Slowbro, Stored Power Necrozma, Mega Gyarados, Chansey, and Blissey can all fill this role. In exchange, Kommo-o can beat most Dark- and Fighting-type Pokemon such as Mega Gyarados, Greninja, Pheromosa, and Keldeo. Besides the aforementioned, Kommo-o appreciates Pokemon that universally cover Dragon-types, as, except for Zygarde, they all have favorable matchups against Kommo-o. Pokemon that can beat every viable Dragon-type in the metagame include Mega Diancie and specially defensive Mega Altaria. Sturdy users such as Magnezone, Crustle, Donphan, and Carracosta can also serve as excellent teammates, as they can tank overwhelming offensive moves that Kommo-o has trouble with, such as a Breakneck Blitz from Porygon-Z and Outrage from Mega Charizard X, and hit back hard. Magnezone is especially relevant, as it can take on Fairy-type Pokemon in the tier. In return, Sturdy Pokemon appreciate the favorable matchups Kommo-o has against traditional Sturdy breakers such as Mega Gyarados and Mega Lopunny.