Lairon

This set remedies Lairon's Speed issue, allowing it to cause serious damage to the foe's team when played correctly. Head Smash with STAB and Life Orb is a devastating attack to any foe that doesn't resist it, especially when no recoil damage from it is received to Lairon thanks to Rock Head. Earthquake provides Lairon with the Rock/Ground attack combination, only being resisted by Bronzor, who can barely do anything to Lairon as it stands. Iron Tail has poor accuracy, but is Lairon's only option to take out some of its biggest counters otherwise, these being Rhydon, Graveler, Nosepass, and Machoke.

An Adamant nature is used to take full advantage of Lairon's immense power. With the given nature, EV spread, and a Life Orb, Lairon is able to OHKO 4/0 Adamant Rhydon and 252/0 Impish Nosepass with Stealth Rock damage, 2KO all Machoke, and always OHKO 252/0 Adamant Graveler. Bronzor will always be 3KOed by Head Smash, assuming all three hit. However, a Jolly Nature with 196 Speed allows Lairon to outspeed a max Speed Sneasel after a single Rock Polish. Lairon can outspeed a Choice Scarf Staravia and Quilava with an investment of 248 Speed, although neither can do serious damage to Lairon bar Hidden Power Water on Quilava, and using 60 Special Defense EVs ensures that Lairon is never OHKOed by said Hidden Power Water. If a Jolly nature is chosen, it is advisable to have solid counters for each of the Pokemon mentioned above as Lairon will not be able to defeat them and will require team assistance.

The idea behind this set is simple: Switch in on a resisted attack or a weak attacker like Staravia, click Head Smash, and be assured you are doing at least 40% damage or higher to everything in NFE not named Impish Rhydon, Lairon, or max HP/Def Metang. With this absurdly powerful Head Smash, just about half of the NFE OU tier is OHKOed. The remaining half are all either 2KOed by said Head Smash, or beaten by another move. Rhydon is taken out by Iron Tail, Marshtomp is possibly 2KOed by Double Edge, and even though Bronzor resists everything that Lairon can throw at it, Lairon still deals 40% minimum with Head Smash while Bronzor can do nothing in return.

The major downfall of this set is how vulnerable it is after a kill. With only 179 Speed, a terrible Special Defense stat, and two common 4x weaknesses, saying this set is easy to revenge is a gross understatement. Lairon's insane 316 Defense stat, which is actually higher than its max Attack stat, goes some way toward helping this but is just not enough. Diglett is the mortal enemy of this set, revenge-killing Lairon with one swift Earthquake while the iron beast has no way to run. Scouting for Diglett before sending this Lairon out is recommended, though if Lairon has a sweeper like Swords Dance Grovyle waiting for a choice-locked Earthquake then it may not be such a poor idea to use Lairon recklessly. Sunny Day Tangela also makes an effective partner, as it loves to set up on weak Earthquakes to gain a Chlorophyll boost and use Solarbeam effectively. Tangela also will easily dispose of Marshtomp and Rhydon, further easing any reservations that one may have about spamming Lairon's Head Smash recklessly.