

Toxapex @ Black Sludge
Ability: Regenerator
EVs: 252 HP / 100 Def / 156 SpD
Bold Nature
- Scald
- Toxic Spikes / Baneful Bunker
- Recover
- Haze / U-Turn
So, of course Scald is the mandatory broken move that always burn the opponent and helps out Toxapex versus phisically threats, while Recover is the mandatory recovery(lol). On the last two slots I put Toxic Spikes, that could be replaced with Baneful Bunker if you want to, and Haze to not being pressured by setuppers. U-Turn is also a good option on the last slot to have a really good slow turner on the team to keep the momentum up. I'll put some calcs to show you how bulk this mon is.
252 SpA Choice Specs Keldeo Hydro Pump vs. 252 HP / 156 SpD Toxapex: 88-104 (28.9 - 34.2%) -- 2.3% chance to 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Mega Lopunny Return vs. 252 HP / 100+ Def Toxapex: 102-121 (33.5 - 39.8%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
+2 252+ Atk Mega Scizor Knock Off (97.5 BP) vs. 252 HP / 100+ Def Toxapex: 152-179 (50 - 58.8%) -- guaranteed 2HKO after Stealth Rock and Black Sludge recovery
+2 252+ Atk Mega Scizor Knock Off vs. 252 HP / 100+ Def Toxapex: 102-121 (33.5 - 39.8%) -- guaranteed 3HKO after Stealth Rock
252 Atk Tough Claws Mega Charizard X Dragon Claw vs. 252 HP / 100+ Def Toxapex: 102-120 (33.5 - 39.4%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252+ Atk Mega Heracross Rock Blast (5 hits) vs. 252 HP / 100+ Def Toxapex: 115-140 (37.8 - 46%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Choice Band Weavile Knock Off (97.5 BP) vs. 252 HP / 100+ Def Toxapex: 133-157 (43.7 - 51.6%) -- 66.8% chance to 2HKO after Stealth Rock and Black Sludge recovery
252 Atk Choice Band Weavile Knock Off vs. 252 HP / 100+ Def Toxapex: 90-106 (29.6 - 34.8%) -- guaranteed 3HKO after Stealth Rock
252+ Atk Choice Band Huge Power Azumarill Knock Off (97.5 BP) vs. 252 HP / 100+ Def Tentacruel: 113-134 (37.1 - 44%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252+ SpA Mega Charizard Y Fire Blast vs. 252 HP / 156 SpD Toxapex in Sun: 113-133 (37.1 - 43.7%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 SpA Life Orb Gengar Shadow Ball vs. 252 HP / 156 SpD Toxapex: 113-134 (37.1 - 44%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Mega Altaria Earthquake vs. 252 HP / 100+ Def Toxapex: 114-136 (37.5 - 44.7%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Life Orb Pheromosa High Jump Kick vs. 252 HP / 100+ Def Toxapex: 84-100 (27.6 - 32.8%) -- guaranteed 4HKO after Stealth Rock and Black Sludge recovery
252 Atk Life Orb Marshadow Spectral Thief vs. 252 HP / 100+ Def Toxapex: 109-130 (35.8 - 42.7%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Mega Lopunny Return vs. 252 HP / 100+ Def Toxapex: 102-121 (33.5 - 39.8%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
+2 252+ Atk Mega Scizor Knock Off (97.5 BP) vs. 252 HP / 100+ Def Toxapex: 152-179 (50 - 58.8%) -- guaranteed 2HKO after Stealth Rock and Black Sludge recovery
+2 252+ Atk Mega Scizor Knock Off vs. 252 HP / 100+ Def Toxapex: 102-121 (33.5 - 39.8%) -- guaranteed 3HKO after Stealth Rock
252 Atk Tough Claws Mega Charizard X Dragon Claw vs. 252 HP / 100+ Def Toxapex: 102-120 (33.5 - 39.4%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252+ Atk Mega Heracross Rock Blast (5 hits) vs. 252 HP / 100+ Def Toxapex: 115-140 (37.8 - 46%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Choice Band Weavile Knock Off (97.5 BP) vs. 252 HP / 100+ Def Toxapex: 133-157 (43.7 - 51.6%) -- 66.8% chance to 2HKO after Stealth Rock and Black Sludge recovery
252 Atk Choice Band Weavile Knock Off vs. 252 HP / 100+ Def Toxapex: 90-106 (29.6 - 34.8%) -- guaranteed 3HKO after Stealth Rock
252+ Atk Choice Band Huge Power Azumarill Knock Off (97.5 BP) vs. 252 HP / 100+ Def Tentacruel: 113-134 (37.1 - 44%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252+ SpA Mega Charizard Y Fire Blast vs. 252 HP / 156 SpD Toxapex in Sun: 113-133 (37.1 - 43.7%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 SpA Life Orb Gengar Shadow Ball vs. 252 HP / 156 SpD Toxapex: 113-134 (37.1 - 44%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Mega Altaria Earthquake vs. 252 HP / 100+ Def Toxapex: 114-136 (37.5 - 44.7%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
252 Atk Life Orb Pheromosa High Jump Kick vs. 252 HP / 100+ Def Toxapex: 84-100 (27.6 - 32.8%) -- guaranteed 4HKO after Stealth Rock and Black Sludge recovery
252 Atk Life Orb Marshadow Spectral Thief vs. 252 HP / 100+ Def Toxapex: 109-130 (35.8 - 42.7%) -- guaranteed 3HKO after Stealth Rock and Black Sludge recovery
Toxapex @ Black Sludge
Ability: Merciless
EVs: 252 HP / 4 Def / 252 SpA
Modest Nature
- Scald
- Venoshock
- Recover
- Toxic Spikes
So, Toxic Spikes is pretty mandatory to activate the Venoshock+Merciless combination, while Scald is here to not being walled by Steel and Poison-types(also is a broken move so why not use it for random burns? xd). Recover is to keep Toxapex healthy throughout the match since it hasn't Regenerator anymore.
Just to show you how hard it hits:
252+ SpA Toxapex Venoshock (130 BP) vs. 252 HP / 0 SpD Mew on a critical hit: 202-238 (50 - 58.9%) -- guaranteed 2HKO after Leftovers recovery and poison damage
252 SpA Life Orb Thundurus Thunderbolt vs. 252 HP / 0 SpD Mew: 187-220 (46.2 - 54.4%) -- 4.7% chance to 2HKO after Leftovers recovery
252+ SpA Toxapex Venoshock (130 BP) vs. 252 HP / 84+ SpD Clefable on a critical hit: 366-432 (92.8 - 109.6%) -- 56.3% chance to OHKO
252 SpA Life Orb Thundurus Thunderbolt vs. 252 HP / 0 SpD Mew: 187-220 (46.2 - 54.4%) -- 4.7% chance to 2HKO after Leftovers recovery
252+ SpA Toxapex Venoshock (130 BP) vs. 252 HP / 84+ SpD Clefable on a critical hit: 366-432 (92.8 - 109.6%) -- 56.3% chance to OHKO