Moves
Tank Bronzong is a flagship set in the DPP metagame. This set takes advantage of Bronzong's above-average mixed bulk and wonderful defensive typing in order to sponge as many hits as possible, which in turn allows Bronzong to shut down a vast array of threats, providing it some momentum to set up Stealth Rock. This set is incredibly reliable against offensive archetypes because it's tough to beat and hits frail enemies hard. However, it has some trouble pressuring bulkier teams, which often feature Skarmory and other allies that can sponge its attacks. This includes bulky Starmie with Recover + Rapid Spin that can potentially keep Bronzong's entry hazards away, but a fast 3 Attacks + Rapid Spin set is significantly pressured. Gyro Ball is Bronzong's strongest STAB attack overall, doing great neutral damage to anything bar slow enemies like Clefable. Alternatively, Bronzong can opt for coverage with Hidden Power Ice to avoid PP issues and deal with Gliscor, Dragonite, Flygon, and Breloom at the same time, while Payback is a great offensive tool to pressure foes like Starmie, Gengar, Rotom, and Latias. Earthquake enables Bronzong to hit Infernape and Steel-types like Magnezone and Heatran, which otherwise laugh at it. Toxic horribly cripples Water-types such as Suicune, Milotic, Swampert, and Gyarados and other foes that resist its moves like Zapdos and Rotom-A. It can also surprise stallbreaker Gliscor, which doesn't always want to Taunt Bronzong straight away. Protect is a useful alternative to scout Choice item users and pick up additional Leftovers recovery that can also be used with Toxic to rack up additional damage. Another option worth considering is Explosion, which allows Bronzong to check a problematic foe and stops threats like Gyarados and Suicune from setting up on it.
Set Details
Mixed bulk is great to let Bronzong handle a wide array of both physically and specially oriented sweepers. 252 HP EVs maximize Bronzong's poor base HP, which is optimal for maximized durability. 128 Special Defense and Defense EVs with a Sassy nature make for a great emphasis on mixed bulk, allowing Bronzong to sponge common special attacks such as Draco Meteor, Fire Blast, Hidden Power Fire, Shadow Ball, and Hydro Pump as well as avoid being worn down too quickly by physical attackers like Jirachi, Tyranitar, Gyarados, and Swampert. Levitate grants Bronzong the opportunity to check Ground-types, such as Mamoswine and Flygon, which its typing wouldn't normally allow it to do. Additionally, Bronzong's Sassy nature and 0 Speed IVs decrease its Speed to make Gyro Ball stronger, though its nature should be Careful if you do not use it. Leftovers provides a form of passive recovery, which is crucial on such a defensive Pokemon.
Usage Tips
Bronzong should be used as a pivot throughout the match. Take advantage of the great number of Pokemon Bronzong checks and use any given opportunity to set up Stealth Rock. However, keep in mind that it lacks reliable recovery and can get worn down pretty quickly. Similarly, Bronzong does not appreciate losing its Leftovers, so be wary of Knock Off when facing foes like Gliscor, Clefable, and Empoleon. If you are using Protect, be careful to not use it excessively when there are Pokemon on the opposing team that can use Bronzong as setup bait, such as Breloom and Skarmory. If you spot a Choice-locked Pokemon, use Protect to scout it out. Keep Toxic concealed for a bit to increase its surprise value and potentially land it on a foe like Gliscor or Milotic. Be also careful not to waste Gyro Ball's low PP too quickly, since it can be stalled out over the course of a game, especially by Pressure users like Suicune and Zapdos. Use Gyro Ball on more offensive Starmie and Earthquake on more defensive ones, which do not run maximum Speed investment. If you suspect your opponent is running an archetype that could feature Magnezone, try to hit it with Earthquake as it may switch in.
Team Options
This Bronzong set tends to work well on its own and does not requires specific support from its teammates, as its objective is basically to set up Stealth Rock and attack opposing Pokemon with Gyro Ball or cripple them with Toxic. However, Bronzong fits best on balanced teams that can take advantage of its resistances and durability. Water-types such as Suicune and Starmie appreciate Bronzong's ability to switch into almost any variant of Latias as well as Grass-types such as Celebi, while they deal with Bronzong's lone Fire-type weakness. The same goes for Swampert, but you should be careful about not giving Breloom too many opportunities to come in, as it can be relatively annoying to handle for balanced teams. If you're using Water-types alongside Bronzong, Pokemon such as Latias and Zapdos work well alongside the bell, as they are both great counters to Breloom and provide a welcome Fighting resistance. On top of that, Zapdos helps deal with Water-types, which give Bronzong some trouble. Therefore, a core of Bronzong + Zapdos + Starmie provides a great defensive balance with an interesting offensive synergy. More generally, Pokemon that can sponge attacks from Fire-types and force them out are always great teammates to consider. This makes any Dragon-type a great teammate. Dragonite helps deal with Breloom and Fire-type moves, but you should keep in mind that switching into Stealth Rock repeatedly can wear it down quickly.
Tyranitar is always a good teammate because it is a solid check for Starmie and Rotom-A, provides support against Zapdos, and resists Fire-type moves while getting up sandstorm, which chips down some of Bronzong's checks, whereas Bronzong is immune to it. As for example, Starmie, Rotom-A, and Breloom are limited in their use by sand. Another support option to consider is Toxic Spikes, since it allows Bronzong to stall out Water-types and cripple foes like Infernape and Tyranitar. With the use of Protect and sand damage, it will be even more effective. Nidoqueen in particular is great at doing this job alongside Bronzong, as it provides a solid Fighting-type resistance and can switch into Zapdos or Tyranitar to put Toxic Spikes up. Heatran works well by its side, as it can sponge Fire-type attacks and take advantage of Toxic Spikes with moves like Substitute, Magma Storm, and Protect while completing a solid defensive core. You should consider covering the Water-type weakness, however. Rotom-A also makes great use of Toxic Spikes, since it can deny Starmie's Rapid Spin and make Tyranitar suffer when it switches into Thunderbolt alongside poison damage. As Bronzong lacks a reliable instant recovery move, Wish users such as Clefable, Jirachi, and even Latias can help improve its longevity.
Skarmory is one of Bronzong's bigger threats due to its ability to stack Spikes freely against it. By annihilating Skarmory, Magnezone naturally provides great support. Magnezone also helps at dealing with other Steel-types such as Scizor, Jirachi, Bronzong, and even Swords Dance Lucario if running Choice Scarf. The combination of Magnezone and tank Bronzong works on both offensive and defensive teams. Dragon Dance Dragonite and Choice Specs Latias would make great additions for an offensive approach, while Milotic or defensive Latias would complete a synergistic defensive core. Finally, Starmie is another great teammate to consider for Rapid Spin, especially if you run Dragonite or Zapdos. It also covers Fire-type moves and carries Thunderbolt to weaken Water-types for Bronzong. Your own Electric- and Grass-types in general can also serve well to wear down and threaten bulky Water-types.