Rate my Gen 8 National Dex OU Set

Question

This set has won a couple battles and even a few tournaments somehow, but it has a couple weaknesses, and I'm not sure what to fix while not changing the Pokemon, I also don't have a proper lead

Infernape @ Focus Sash
Ability: Iron Fist
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Brick Break
- Fire Punch
- Thunder Punch

Infernape's purpose is to be a physical sweeper, Iron Fist makes it so Fire Punch and Thunder Punch are 90 BP, and I'm running Thunder Punch over Stone Edge, as missing would be a problem in this set. Brick Break over Close Combat because I don't want lowered defenses, and I want to break screens (I'm not sure if either of these are problems for the set though). Swords dance is to stat buff while tanking with Focus Sash, stage hazards are clearly a problem with this though.

Swampert-Mega @ Swampertite
Ability: Torrent
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Earthquake
- Liquidation
- Ice Punch
- Flip Turn

This is one of the two sets I've posted on "What is a good moveset for ...", so this'll be brief, Earthquake and Liquidation for STAB, Flip Turn to pivot, and Ice Punch for coverage

Serperior @ Assault Vest
Ability: Contrary
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Leaf Storm
- Dragon Pulse
- Giga Drain
- Hidden Power [Ice]

I've seen many Serperior sets being mixed attackers, but I just wanted a Special Attacking one. Leaf Storm for STAB and the Sp. Atk buff with Contrary, Dragon Pulse is coverage, Giga Drain is to recover, and Hidden Power Ice is coverage against flying types.

Pelipper @ Damp Rock
Ability: Drizzle
EVs: 248 HP / 252 Def / 8 SpA
Bold Nature
IVs: 0 Atk
- Hurricane
- Surf
- Defog
- Roost

We all know you can't run Mega Swampert without Drizzile Pelipper. Hurricane and Surf are STAB, and Hurricane is accurate in the rain. Defog is to clear hazards, and Roost is to recover. Tyranitar always causes problems when I use this guy

Quagsire @ Leftovers
Ability: Unaware
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Scald
- Encore
- Recover
- Toxic

Hey, another set I posted! I tried it in National Dex even though it was created for Gen 8 PU, and it did pretty well! Encore to trap your opponent into a move, Scald for a STAB move that has a chance to burn, Recover to... Recover, and Toxic's use is pretty self-explanatory

Hydreigon @ Dragonium Z
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Dragon Pulse
- Dark Pulse
- Flamethrower
- Earth Power

Hydreigon's use is pretty self-explanatory, Dragon Pulse and Dark Pulse are STAB, Flamethrower is Ice and Bug coverage, and Earth Power is also coverage. Dragonium Z's use is simple, for Dragon Pulse to be turned into Devastating Drake

Answer 1

Infernape --> Corviknight

If you wanted a physical Fire type you'd use Victini or Blaziken. However, why even use a Fire type if it's a rain team? Rain's biggest checks are Rillaboom, Scarf Kartana, and Kyurem. Having a Pokemon that can handle them is important. Corviknight is the only one that can beat all 3 (to some extent) which fits on rain teams, since rain obviously can't have Mega Scizor and Zapdos is generally using an offensive set. Sub Bulk Up Corviknight PP stalls and beats those Pokemon + other annoyances to rain like Ferrothorn, Mega Latias, etc, and can sweep late game with Spikes support. Pelipper is already your Defogger and this is a more high-octane team so Defog is less valuable, however if you want to use the Defog set that's perfectly fine.

Corviknight @ Leftovers
Ability: Pressure
EVs: 252 HP / 44 Def / 144 SpD / 68 Spe
Impish Nature
- Brave Bird
- Bulk Up
- Substitute
- Roost

Corviknight @ Leftovers
Ability: Pressure
EVs: 252 HP / 184 Def / 72 SpD
Impish Nature
- Brave Bird / Body Press
- U-turn
- Roost
- Defog

Swampert

Jolly > Adamant to outspeed Scarf Kartana during rain. Waterfall's chance to flinch is generally better than Liquidation, and Liquidation also doesn't improve any notable damage rolls.

Serperior --> Manaphy

Assault Vest Serperior goes against what Serperior is supposed to do, as if using it on rain isn't big enough of a crime itself. Part of Serperior's game is using Glare on stuff. Serperior also needs rain to not be present so that it can actually damage Ferrothorn and Corviknight with Hidden Power Fire. Glare is less needed on a rain team,
Zapdos beats Waters, so Serperior is best replaced with Manaphy, who absolutely destroys any defensive answers rain teams have.

Manaphy @ Waterium Z
Ability: Hydration
EVs: 248 HP / 240 SpA / 20 Spe
Modest Nature
- Surf
- Tail Glow
- Rest
- Energy Ball

Pelipper

U-turn > Hurricane for being able to bring in the team's offensive threats with more ease. Also, Scald over Surf to be able to punish most things for switching in even further. Also 8 SpD over 8 SpA because Pelipper isn't meant to do immediate damage.

Quagsire --> Zapdos

Quagsire is only good on stall, which is the only place where Unaware is really needed. Zapdos is better on rain as an offensive threat that comes with the benefit of beating Water resists.

Zapdos @ Heavy-Duty Boots
Ability: Static
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Thunder
- Hurricane
- Weather Ball
- Roost

Hydreigon --> Ferrothorn

Why would you be using z-move Hydreigon without Nasty Plot? Hydreigon doesn't benefit from rain much and the Z-move slot is taken by Manaphy anyway, so Ferrothorn is a good choice here. It can use Spikes, offers a defensive backbone, and appreciates Rain weakening Fire type moves.

Ferrothorn @ Leftovers
Ability: Iron Barbs
EVs: 252 HP / 24 Def / 232 SpD
Careful Nature
- Spikes
- Leech Seed
- Body Press
- Knock Off

Pokepaste (Sub Bulk Up Corviknight)

Pokepaste (Defog Corviknight)