The viability thread strongly disfavors Conkeldurr largely due to its lack of power, 4MSS (resulting in a very predictable moveset), most of its moves having contact (against Ferrothorn and Aegislash), presence of flying spam (and especially Mega Pinsir and set-up variants of Talonflame that can set-up on it) and powerful Psychic coverage moves to beat Mega Venusaur, and low speed. Its low speed makes it practically unsalvageable, and even if one maxes out its attack to deal with Mega Mawile with Earthquake, it has the disadvantage of being faster than Aegislash. The low speed prevents it from apply any offensive pressure to most dedicated physical walls, particularly Skarmory and Mandibuzz, but it can outspeed Chansey, Hippowdon, and Blissey (and perhaps Fairies if they are really considered "walls") by trying toying with the EVs to creep them. (It can, thankfully, outspeed Gastrodon, Tangrowth, Slowbro, and Ferrothorn). This lack of pressure from its low speed prevents it from killing even a weakened wall in range for Conkeldurr's Drain Punch (25%-30% for a AV unstatused Conkeldurr) or a Supereffective elemental punch (32-39%). Conkeldurr's low speed, however, can be a redeeming factor against common Roost users, since, if it predicts the Roost can score a STABs super-effective hit while also healing itself (but watch out from Rocky Helmet).
I was trying to replace Landorus-T on a team with Azumarill, Thundurus-I, Latios, Heatran, and Scizor. The problem is that Lando-T has a rather nasty Water and 4x Ice weakness, as there are two other Ice weaknesses and Heatran being weak to Water. The Water weakness is relevant since Greninja could just use a Water attack on Lando-T thus making it resistance to my priority users. In other words, the team is weak against special sweepers (e.g. Thundurus-I, Manectric, Starmie, and Greninja, and to a lesser extent, Latios if it wins a speed tie against my Latios or is strong enough to take an HP Ice from my Thundurus).
Keldeo would not work as a fighting type since it is weak to electricity and adds a weakness to Latios. Since Latios and Thundurus have Life Orbs as the are coverage sweepers, Tyranitar is strongly discouraged. Ferrothorn may work but it depends on the presence of Focus Blast on Thundurus and fails against Manectric. So, Conkeldurr seems to be the best option. Now, with Lando-T gone, I do not have a check to Mega Mawile (Adamant Max Attack Earthquake with Intimidate can take a 2+ Sucker Punch and KO the bulkiest variant) or something that can deal with Aegislash aside from Heatran.
This set is slower than Aegislash and can take a Shadow Ball, however, its efficacy relies on it being faster than Mega Mawile:
Conkeldurr @ Assault Vest
Ability: Guts
Happiness: 0
EVs: 252 Atk / 204 SDef / 52 Spd
Adamant Nature
- Mach Punch
- Drain Punch
- Earthquake
- Knock Off
The calcs:
252+ Atk Conkeldurr Earthquake vs. 252 HP / 0 Def Aegislash-Shield: 180-212 (55.5 - 65.4%) -- guaranteed 2HKO after Leftovers recovery
252+ Atk Conkeldurr Earthquake vs. 252 HP / 0 Def Mega Mawile: 210-248 (69 - 81.5%) -- guaranteed 2HKO
Without Ice Punch, it does not cleanly KO Landorus-T/I (requiring another Pokemon necessary to clean up after it uses Knock Off while Lando-I/T could just retreat and come back when it is safer but at least their item is removed) or allow it to play mind games with Pokemon such as Zapdos and Mandibuzz as it can threaten Drain Punch on the Roost turn while threatening a super-effective hit (in the case of Zapdos using Knock Off occasionally might be necessary to preserve Drain Punch/Ice Punch PP), but the damage from Earthquake is enough for Mega Scizor's to finish the job or speed creeping Azumarill.
For the Fairies if they switch in or if you outspeed them:
252+ Atk Conkeldurr Earthquake vs. 252 HP / 0 Def Sylveon: 180-212 (45.6 - 53.8%) -- 2.3% chance to 2HKO after Leftovers recovery
252+ Atk Conkeldurr Earthquake vs. 252 HP / 252+ Def Sylveon: 119-141 (30.2 - 35.7%) -- guaranteed 4HKO after Leftovers recovery
252+ Atk Conkeldurr Earthquake vs. 252 HP / 0 Def Azumarill: 153-180 (37.8 - 44.5%) -- guaranteed 3HKO
252+ Atk Conkeldurr Earthquake vs. 252 HP / 252+ Def Clefable: 111-131 (28.1 - 33.2%) -- 91.7% chance to 4HKO after Leftovers recovery
You also lose the ability to hit Togekiss on the switch.
Now, the question is how desperate I am to defeat the possible Mega Mawile with a Conkeldurr? The 1695 usage statistics indicate around 40% invested only 4 points or less in its speed, with ~15% with either 124 or 132 to outspeed non-Mega Scizor's Bullet Punch. We can assume that those the other spreads are used to outspeed things such as Sylveon before it can use Heal Bell or Wish as its way to make a productive sacrifice. If one is willing to invest enough to outspeed the Mawile that outspeed Scizor, then what is the additional cost of additional speed and boosting items and abilities to outspeed Mandibuzz and Skarmory worth it relative to the lost bulk and lack of Guts?
Die, Skarmory, Die? (Conkeldurr) @ Life Orb
Ability: Sheer Force
EVs: 252 Atk / 252 Spd
Jolly Nature
- Drain Punch
- Thunder Punch
- Earthquake
- Knock Off
Mach Punch is omitted because it is weak and Conkeldurr is now so fast that it is unnecessary... I do not know the practical merit of speedy, lure Conkeldurr. Unfortunately, it cannot outspeed 44 Speed Rotom-W.
Here are the relevant damage offensive calcs:
252 Atk Life Orb Sheer Force Conkeldurr Thunder Punch vs. 252 HP / 252+ Def Mandibuzz: 205-244 (48.3 - 57.5%) -- 51.6% chance to 2HKO after Leftovers recovery
252 Atk Life Orb Sheer Force Conkeldurr Thunder Punch vs. 252 HP / 232+ Def Skarmory: 169-200 (50.5 - 59.8%) -- guaranteed 2HKO
252 Atk Life Orb Conkeldurr Earthquake vs. 252 HP / 0 Def Mega Mawile: 250-294 (82.2 - 96.7%) -- guaranteed 2HKO
252 Atk Life Orb Conkeldurr Earthquake vs. 252 HP / 0 Def Aegislash-Shield: 211-250 (65.1 - 77.1%) -- guaranteed 2HKO after Leftovers recovery
Now some sample defensive damage calcs:
252 SpA Life Orb Protean Greninja Ice Beam vs. 0 HP / 4 SpD Conkeldurr: 231-273 (65.8 - 77.7%) -- guaranteed 2HKO
252 SpA Life Orb Greninja Hydro Pump vs. 0 HP / 4 SpD Conkeldurr: 281-331 (80 - 94.3%) -- guaranteed 2HKO
252 SpA Life Orb Thundurus Thunderbolt vs. 0 HP / 4 SpD Conkeldurr: 263-309 (74.9 - 88%) -- guaranteed 2HKO
Now, relative to the Assault Vest:
252 SpA Life Orb Thundurus Thunderbolt vs. 252 HP / 4 SpD Assault Vest Conkeldurr: 175-208 (42.2 - 50.2%) -- 0.4% chance to 2HKO
As one can see, this Conkeldurr is not really Conkeldurr anymore as the speedy Conkeldurr takes ~1.6 times more per special attack. It forfeited its ability to check special attackers, and this set is of dubious value.