Hi! This is a pretty interesting team that I think is off to a good start. I think a big problem with this team is that there isn't much speed control and not enough defensive pressure to handle powerful offensive teams. A lot of it has to do with the sets that you chose not being the most optimal for this team, but I also think that a couple pokemon can be replaced to better help with this issue.
I'll first start off with Infernape. I used to enjoy playing with a mixed Infernape set back in ORAS OU as a niche threat to common defensive cores, but SMOU has introduced offensive threats that can outclass it like Blacephalon, as well as defensive threats like Toxapex that make it harder for Infernape to break through defensive teams. As such, Infernape has been rendered more obsolete in the OU tier in Sun and Moon to the point where it just isn't really viable anymore. I think a better pokemon to use on this team instead of Infernape is Utility Heatran.
Heatran @ Leftovers
Ability: Flash Fire
EVs: 252 HP / 4 SpA / 252 Spe
Timid Nature
- Magma Storm
- Earth Power
- Taunt
- Stealth Rock
Utility Heatran provides a number of advantages to your team over Infernape. This Heatran set gives you additional counterplay versus stall teams as well as giving you another check to Tapu Lele, which can be very threatening to your team. I added Stealth Rock over Toxic because I plan on removing Stealth Rock from your Landorus-Therian and I wanted a new hazard setter for the team.
SD Bisharp has the ability to deal a lot of damage to various defensive pokemon such as Ferrothorn and Tangrowth at +2 that would otherwise be roadblocks for Mega Gyarados to sweep when they're at full health. However, against offensive teams, I believe that Bisharp would have a hard time finding an opportunity to set up due to its frailty. Furthermore, Bisharp is unable to pick off pokemon such as Mega Lopunny and Keldeo that are capable of revenge killing Mega Gyarados unless they've been weakened. This also goes for other offensive pokemon with enough bulk to live a +2 Sucker Punch from full. To alleviate the lack of speed control to deal with offensive teams, I suggest replacing Bisharp with Shift Gear Magearna.
Magearna @ Fairium Z
Ability: Soul-Heart
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Shift Gear
- Fleur Cannon
- Thunderbolt
- Focus Blast
Magearna retains a steel type breaker for your team, but what Magearna has over Bisharp is the ability to boost its Speed via Shift Gear to outspeed and KO some of the aforementioned offensive threats that Bisharp can't. Having Magearna over Bisharp also gives you a second Tapu Lele check that's better than Bisharp due to Magearna's typing allowing it to resist Moonblast. Fairium Z on the Magearna allows it to deal large amounts of damage to defensive pokemon like Tangrowth and Clefable that Bisharp was able to handle with Swords Dance and weaken or KO them for Mega Gyarados. Magearna also has more natural bulk compared to Bisharp which can allow it take hits better, which is useful for the bulky nature of this team.
Next I'm gonna list some set changes for the rest of your pokemon. As I said earlier, this team looks like it's in some need of speed control. I wanted the team to have something that could immediately revenge kill threats and not just Magearna which has to set up first. In order to have that, I decided to change your Landorus-Therian set to a Choice Scarf Landorus-Therian.
Landorus-Therian @ Choice Scarf
Ability: Intimidate
EVs: 80 HP / 148 Atk / 84 Def / 196 Spe
Naive Nature
- Earthquake
- U-turn
- Hidden Power Ice
- Defog
As listed on the Smogon analysis for Landorus-Therian, the EVs on this set allow for Landorus-Therian to live two unboosted Leaf Blades from Kartana after Stealth Rock while also being able to outspeed Mega Alakazam and anything slower than it.
Tangrowth should be running an Assault Vest set in order to better deal with powerful special attackers like Greninja.
Tangrowth @ Assault Vest
Ability: Regenerator
EVs: 252 HP / 28 Def / 228 SpD
Sassy Nature
- Giga Drain
- Knock Off
- Hidden Power Ice
- Earthquake
Finally, Toxapex should be running Haze over Stockpile since its defenses are already incredibly good and thus doesn't need to boost its defenses even more. Haze allows for Toxapex to get rid of stat boosts which could potentially be useful against set-up sweepers. Additionally, Mega Gyarados should have its 4 HP EVs moved to Special Defense. This allows Mega Gyarados to have an odd HP number, which means that it can switch into Stealth Rock one additional time. Toxapex should change its spread to 248 HP/252 SpD/8 Def in order to be bulkier on the Special side to handle pokemon like Greninja better.
I tried not to replace more than two pokemon on your team, so this might not be as optimal of a team as it could be, but I think these changes improved some of the issues with this team. I hope this helps! Also, I'm not sure if you only wanted to use this for Wi-Fi battles, since you mentioned getting your Landorus-Therian from a trade. If some of these changes aren't possible for you on your game cartridge, you could always try testing out the team on Pokemon Showdown.
Summary of Changes
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Haze > Stockpile | Change spread to 248 HP/252 SpD/8 Def
Move 4 HP to SpD
Importable
