Clefable
Unaware
Bold nature
252 hp/252 def/4 spdef
- Calm Mind
- Moonblast
- Moonlight
- Flamethrower/Heal Bell/Stealth Rock/Minimize/Stored Power
Simply Clefable. I don't even need to talk about the set actually as almost any physically defensive variant of Clefable easily takes on both of these together, with Selfdestruct coming from 252 adamant Snorlax being the only move that can actually hit Clefable for enough damage to render it useless for some time or to beat it if it isn't at full health (and forcing one half of a core to selfdestruct leaves it broken). Unaware-Clef stomps on Curselax, using it as setup-bait while also being able to live 3 body slams from the curseless offensive set sometimes, which lacks any recovery, meaning it will win against almost every Snorlax unless it is really unlucky with the paralysis. Scald-burns from Slowbro may hinder Clefables defensive capabilities and some sets even carry toxic, but thanks to Slowbros lesser special defense and inability to boost with calm mind, Clefable can easily overwhelm any Slowbro daring to stand in its way. Also there is always Magic Guard oder Heal Bell against status (and for those who really need it... Minimize to counter Body Slams cheap luck-tactic with your own cheap luck).
Some calcs:
252+ Atk Snorlax Body Slam vs. 252 HP / 252+ Def Clefable: 63-75 (31.1 - 37.1%) -- 77.8% chance to 3HKO
252+ Atk Snorlax Self-Destruct vs. 252 HP / 252+ Def Clefable: 147-174 (72.7 - 86.1%) -- guaranteed 2HKO
0 Atk Snorlax Body Slam vs. 252 HP / 252+ Def Unaware Clefable: 46-55 (22.7 - 27.2%) -- 50.2% chance to 4HKO
4 SpA Slowbro Scald vs. 252 HP / 4 SpD Clefable: 51-60 (25.2 - 29.7%) -- guaranteed 4HKO
+1 0 SpA Clefable Moonblast vs. 252 HP / 4 SpD Slowbro: 93-109 (46 - 53.9%) -- 46.5% chance to 2HKO
after one mere boost, slowbro is already scared out
Another Pokémon that can break apart this core (albeit being a rather shaky check that needs to be played more carefully):
Gyarados
Intimidate
Adamant nature
252 hp/252 atk/4 speed
- Waterfall
- Crunch
- Substitute
- Bounce
This one needs more prediction than just full-stopping them with Unaware-Clef. Using Substitute on a Slowbro that tries to status Gyarados or fishes for a burn grants a free turn to set up while also scouting for T-Bolt. However, a psyshock from Slowbro cleanly breaks the sub even with a minimal roll, but never 3HKOes. At +1, Gyarados can actually 2HKO Slowbro with Crunch, so with smart plays, Gyarados will always emerge victorious here. Against Snorlax, Curse-users are unable to deal meaningful damage at -1 while Gyarados can hit Snorlax very hard even with an unboosted waterfall. Getting lucky with flinches even makes Gyarados position much better after the fight, meaning it can also dish out some damage to slowbro for example. Curseless offensive variants will never 2HKO at -1 except by selfdestructing, leaving them open to enough waterfalls for the KO. Even though Slowbro can switch into most of Gyarados moves to save Snorlax, it will then be overwhelmed by Gyarados most of the time while Snorlax can neither switch into any move nor deal with a boosted Gyarados after it has taken care of Slowbro.
-1 0 Atk Snorlax Body Slam vs. 252 HP / 4 Def Gyarados: 42-51 (20.7 - 25.2%) -- 0% chance to 4HKO
0 Atk Snorlax Body Slam vs. 252 HP / 4 Def Gyarados: 63-75 (31.1 - 37.1%) -- 77.8% chance to 3HKO
252+ Atk Gyarados Waterfall vs. 252 HP / 4 Def Snorlax: 102-121 (38.2 - 45.3%) -- guaranteed 3HKO
252+ Atk Gyarados Waterfall vs. +1 252 HP / 4 Def Snorlax: 67-81 (25 - 30.3%) -- guaranteed 4HKO
-1 252+ Atk Snorlax Body Slam vs. 252 HP / 4 Def Gyarados: 58-69 (28.7 - 34.1%) -- 1.3% chance to 3HKO
+1 252+ Atk Gyarados Waterfall vs. 0 HP / 252 Def Snorlax: 112-133 (47.6 - 56.5%) -- 87.5% chance to 2HKO
0 SpA Slowbro Psyshock vs. 252 HP / 4 Def Gyarados: 55-66 (27.2 - 32.6%) -- guaranteed 4HKO
+1 252+ Atk Gyarados Crunch vs. 252 HP / 252+ Def Slowbro: 100-118 (49.5 - 58.4%) -- 98.4% chance to 2HKO
aaaaaaaaaaaaaaaaaaaaaaaaaaaand last but not least the most offensive (and unsafe) check:
Nidoking
Sheer Force
Naive nature
188 atk / 68 spatk / 252 spd
- Thunderbolt
- Superpower
- Sludge Wave
- Fire Blast
Pretty simple set: TBolt cleanly 2hkoes Slowbro while Superpower gets the 2hko on Snorlax even after the drop. Nidoking is also able to live through one move either of them is using, meaning it can 1v1 both pokemon (however, beware of slowbros scald burns or snorlax with earthquake) while none of them can switch into it safely. Nidoking should only be used if you have the momentum in your favour, as it can't switch into either of them except into a predicted Slack Off from Slowbro. This set also loses to a boosted Snorlax, so a way to force that one out is appreciated. Basically Nidoking is less useful in truly breaking the core but more useful in keeping both pokemon out of the game so the core can't do its work. Becomes very powerful in combination with a strong VoltTurn-User.