Once upon a time, during the grim days of the post Chlorophyll+ Drought ban, evil legions of Spikes-stackers reigned supreme over the kingdom of OU. Then a legend was whispered among the shadows-- that a hero, a knight in shining armor will descend from Mt. Ubers and spin away the forces of darkness. Stripped of his Sand Rush by the Council of Gods, Excadrill has returned to his people(?) as one of the tier's best attackers and supporters and as a shining beacon of BW OU. With two awesome (legal) abilities, almost negligible Stealth Rock vulnerability, a concise but valuable movepool, and the ability to take an Outrage or Draco Meteor in a pinch, Excadrill can show up in teams with vastly different roles and fulfill all of them with aplomb.
Sadly, the second coming of the Subterrene Pokemon has not been too kind to it. While the Choice Scarf set has high utility, usefulness, and sweeping potential, it is underwhelming in speed and can be easily walled depending on which ability you use. As a dedicated entry hazard-remover, having no reliable recovery means that Excadrill can weather the strain of powerful resisted hits only long enough to spin once or twice in a match. It can also be quite awkward to fit into a team due its odd typing and stat-distribution. As an attacker, 88 base speed falls short of many other attackers (notably Keldeo and Landorus-T) that would stop its rampage cold. But rest assured, Excadrill is still Excadrill, and whether that means "scary-as-hell attacker" or "invaluable team asset" one should always be prepared for the threat of a sweep or to have their hard-earned hazards blown away.
name: Choice Scarf
move 1: Earthquake
move 2: Iron Head
move 3: Rock Slide/ Stealth Rock/ Toxic
move 4: Rapid Spin
item: Choice Scarf
ability: Mold Breaker/ Sand Force
nature: Adamant/ Jolly
EVs: 252 Atk / 4 Def / 252 Spe
Scarf Excadrill with Mold Breaker can sweep past Rotom-W, Latios, Bronzong, and Gengar (all of whom take Spikes damage when Excadrill is active). Since it's not expected to be a wallbreaker, it's more amenable to having a Jolly nature. This variant of Scarf Excadrill requires less support and is easy to slap onto a team (being great on weatherless teams and can be used in Sand as well), though it should be noted that its use is fundamentally different from Sand Force and leans more towards support, revenge killing, and being a utility mon that can sweep late-game.
Excadrill's 412 (or more) speed with a Choice Scarf means that once the opponent's hazard setter is down one can sneak in a Rapid Spin against the most relentless of offensive teams. Against a very bulky team that Excadrill will never be putting work against, Stealth Rock is surprisingly not as situational as it may seem- it at least gives it something useful to do while the mole's teammates are wallbreaking. Mold Breaker Stealth Rock will get past Magic Bounce users like Xatu, which is invaluable against some stall match-ups. Toxic is also a viable option as it baits out and wears down Landorus-T, Rotom-W, and Slowbro. Keep in mind that while Stealth Rock and Toxic are worth considering, they are still just more-than-niche options.
Excadrill with Sand Force works fundamentally differently: Sand Force-boosted Adamant Earthquake can achieve 2HKOs on many of the tier's bulkiest Pokemon with hazard support. With just Stealth Rock and sandstorm, Excadrill has a high chance to 2HKO standard Ferrothorn and max defense Slowbro, and with Spikes over Stealth Rock it has a very high chance to 2HKO bulky Breloom with Poison Heal.
Iron Head mops up the rest, dealing lethal amounts of damage to fast-and-frail Psychic and Flying types. It's also useful for chipping Scarfed Landorus-T, and can potentially flinch down your opponent's slower win-conditions. To illustrate just how powerful Sand Force Iron Head is, with just Stealth Rock and sandstorm Excadrill has a 25% chance to OHKO Latios with it, as well as getting an OHKO on Tornadus and a 2HKO on offensive Landorus-T even factoring in Intimidate.
Rock Slide gains a semi-STAB boost from Sand Force and allows Excadrill to weather Rotom-W on the switch as well as achieve revenge kills on Adamant (and some Jolly) Gyarados and Dragonite with as little as 22% HP worth of chip damage.
252 Speed EVs with a neutral nature outruns other Scarf Excadrill, +1 positive-natured Politoed, Dragonite, Gothitelle, and Breloom, and (God forbid somebody brings one in OU) +2 neutral-natured base 50 speed set-up sweepers. Jolly is an option to outrun other Scarf Excadrill and Adamant Scarf Landorus-T, however the only other noteworthy threats it beats are Scarf Heatran (which is rare) and neutral-natured +1 base 100s (Volcarona and Salamence usually run Speed-boosting natures). If you are confident your opponent will bring these, feel free to use Jolly. However, you will miss all the aforementioned kills. 252 Attack with a positive nature allows Excadrill to hit as hard as possible without a damage-boosting item; if you worry about your potential damage output without a Life Orb or such, it is wise to remember that Choice Band Garchomp's Earthquake is only 1.69% stronger than Sand Force Excadrill's. In the unlikely scenario that Excadrill is the only Steel-type on your team, 236 Atk / 20 Def / 252 Spe allows Excadrill to take two unboosted Choice Scarf Salamence Outrages even after Stealth Rock damage. While the above KOs might now be harder to get, in the matchup against a multiple Dragon-type user this could be the difference between a win and a loss.
Scarf Excadrill is not strictly a late-game sweeper or a revenge killer. The combination of sandstorm damage and Excadrill's damage output that equals even Choice Band users (assuming Sand Force) means it can wear down potential checks to make cleaning much easier in the late-game. As such, do not be afraid to bring it out early-to-mid game to help break a wall like Ferrothorn. A conservative approach is preferred when your opponent has a Rotom-W or a Skarmory, however. Your opponent always has an incentive to attack, set up, or switch to a Ghost-type whenever Excadrill is on the field, as every potential attack you make is also a potential Rapid Spin. This is something to take advantage of. Scarf Excadrill is not the kind of Rapid Spinner who should be wantonly switched in and out to clear hazards due to its reduced bulk and inability to switch attacks; rather, a method of using it is to let your opponent pile up their hazards while you deal heavy damage to or KO their hazard-setters. Afterwards is when you clear them all in one go. Conversely, you should always have contingencies for the scenario where Excadrill is locked into Rapid Spin in front of a set-up sweeper or wallbreaker. Using Rapid Spin with this set will leave you locked to it and open to be taken advantage of by set-up sweepers and Iron Barbs/ Rough Skin Pokemon.
Given this variant of Excadrill is only a part-time spinner and is actually not very good at it (being Choiced and all), it is advisable for one to pair it with a team that isn't totally destroyed by entry hazards. Magnezone has excellent synergy with Excadrill and can cage and fry Skarmory as well as hurt bulky Water-types which opens up Excadrill for more aggressive play. Beyond that, obviously a Pokemon that aims to abuse Sand Force must have a Pokemon with Sand Stream supporting it. This means Tyranitar or Hippowdon- of the two, Tyranitar is preferred because it is capable of pressuring and/ or trapping (with a Choice Band) Slowbro, Jellicent, and Reuniclus (all three of which can hamper an Excadrill sweep). Either can also lay Stealth Rock for Excadrill in order to achieve certain KOs. Excadrill is itself not a fast Scarfer- one will either want a second (faster) Scarfer, priority move users, sturdy walls, or situational checks to Dragon Dance/ Quiver Dance users to help control opposing set-up. In particular, Keldeo is a good choice for this. Because it aims to attack as it is without boosting, Spikes are an invaluable asset to Excadrill. Either Skarmory or Ferrothorn are strong options, as they take the pressure off Excadrill in taking the hits that Steel-types should be taking.
It is worth mentioning that Landorus-T can use Gravity to open up for an Excadrill sweep. However, a lot of weaknesses are compunded between the Sand Stream user and those two aforementioned, and one aught to carry a bulky Grass-type of their own so that this strategy doesn't backfire. Sandstorm and Gravity support is usually not necessary for Mold Breaker Excadrill- all the other kinds still apply, however. Latios and Hydreigon greatly appreciate Excadrill. Latios can switch in on the Fire, Water, Ground, and Fighting-type attacks directed at Excadrill, while Excadrill can force out and remove the entry hazards of Tyranitar. Hydreigon can use Fire Blast or Draco Meteor to remove Steel and Ground-types for Excadrill, respectively; Excadrill reciprocates by removing Stealth Rock which U-turn/ Life Orb users like Hydreigon despise.
name: Bulky Rapid Spin
move 1: Earthquake
move 2: Rapid Spin
move 3: Protect
move 4: Toxic/ Iron Head/ Stealth Rock
ability: Mold Breaker
EVs: 228 HP / 252 SpD / 28 Spe
This variant of Excadrill aims to survive as long as possible, to maximize the number of opportunities to use Rapid Spin, and to be capable of using Rapid Spin as often as possible. The moves that are listed here are the limited options with which this can be done: Mold Breaker Earthquake prevents Excadrill from being Taunt and set-up bait and allows Excadrill to attack the Lati siblings (whom you are supposed to use Rapid Spin on), Rotom-W, and Gengar (who could otherwise block your Rapid Spin). Rapid Spin is the support Excadrill provides for its team and allows it to remove entry hazards. Protect serves a triple purpose- it allows Excadrill to compound Leftovers recovery, scout which move a Choice-locked opponent will make (such as Surf from Latios, Stone Edge from Terrakion, Focus Blast from Tornadus, U-turn from Landorus-T, and either of Keldeo's STABs), and to stall out Toxic's gradual increasing effect. Toxic, as mentioned, works in conjunction with Protect and catches spinblockers like Jellicent on the switch and gives Excadrill an option against the likes of Tornadus (which it should be checking)- although one can substitute Iron Head on faster sets. Alternatively, Stealth Rock can be used for role compression but only as a last resort. You don't want to be useless against Flying-types, and Protect is much too useful on this set.
The Speed EVs allow Excadrill to outrun neutral-natured Magnezone with Hidden Power Fire. The rest is dropped into bulk for taking special attacks- Special Defense is maximized first over HP as Excadrill has a huge base 110 HP stat (meaning investment in HP at some point meets diminishing returns). Multiple alternative EV spreads are usable- most notably, 252 HP / 4 Atk / 252 Spe chases down and kills faster Rotom-W while answering Toxicroak, Mamoswine, Heatran, and Kyurem-B in a pinch. 224 HP / 80 Def / 176 SpD / 28 Spe with an Impish nature avoids the 2HKO from Choice Band Garchomp's Outrage after Stealth Rock, while 176 HP / 56 Atk / 180 SpD / 96 Spe with an Adamant nature speed-creeps most specially defensive Rotom-W and knocks them out from full health with Earthquake. This is usually not necessary, however, as most non-attacker Rotoms don't invest too much in Speed nor do they ever show up in front of Excadrill without some form of chip damage (being pivots and all).
This Excadrill is a support unit first and a defensive unit second. Do not just carelessly let it take attacks that more dedicated teammates cannot take in its place. Excadrill should be taking powerful resisted hits, yes, but only when you are sure that you have a reasonable chance of pulling off a Rapid Spin or when failure to do so will cost you the game. Even then, Excadrill will not want for opportunities to pull off a Rapid Spin with all the Tyranitars (even with Choice Band), Jirachis, Amoongusses and Skarmory that roam the tier. It must be emphasized that your interest in preserving Excadrill's HP only extends as far as it is important for you to Rapid Spin. The above EVs can usually take one Lava Plume from specially defensive Heatran or a rain-boosted Scald from defensive Politoed or Tentacruel and pull off a Rapid Spin from full health, and if you absolutely need entry hazards gone do not hesitate to do so and avoid losing the game.
Being a support Pokemon, one should not really be giving it support of its own. However, one can create ideal environments for Excadrill to maximize its capacity to support the team. As a Steel-type, it's rather bad at fulfilling the duties of a Steel-type- it appreciates teammates that can take physical hits for it and the presence of another Latios buffer (such as Landorus-T and Jirachi, respectively). This Excadrill is at home in slower balance or defensive builds, where it can clear Spikes for deadly breakers like Substitute Jirachi (CM or 3 attacks) or Substitute+ Protect Heatran. On a stall team, Excadrill does not have the capacity to heal itself which means it must rely on Wish from the likes of Alomomola or Chansey to stay healthy in longer games. Stall also appreciates Excadrill's unique defensive niche, compressing checks to non-Focus Blast Thundurus-T, Kyurem-B, and Choice Band Tyranitar in one team-slot. Rain extends Excadrill's longevity against the random Fire-type attacks that people love to slap on their Pokemon, and also allows it to shut down defensive Zapdos builds. Also, there are some Pokemon that Excadrill struggles to spin against (see: Rocky Helmet spikers and Garchomp) and having a team that can neuter them is essential for good results. Mew and Jellicent can Taunt these nuisances and burn them with Will-O-Wisp.
Excadrill doesn't have many other viable options. A Sand Force attacker set with Earthquake/ Iron Head/ Protect/ Rapid Spin and holding Leftovers makes a terrific wallbreaker, but it greatly desires paralysis support. Substitute could be used to avoid status, ease prediction, and fish for Hydro Pump misses on Rotom-W, but Excadrill is already immune to Toxic and Thunder Wave and it's more productive to just kill the Rotom-W with Mold Breaker Earthquake or switch out if you don't have it. Choice Band with Sand Force hits incredibly hard, but is also too slow and requires exceptional prediction making it most of the time not worth it. It does a strong job of luring Landorus-T, Gliscor, and Hippowdon, however. Magnet Rise is a cool novelty, but Excadrill is already pretty strapped for move slots. In hyper offense teams, Excadrill can serve as a workable lead- Focus Sash Mold Breaker with Stealth Rock and Rapid Spin can prevent other dedicated leads from getting up their Stealth Rock while Excadrill lays its own.
Checks and Counters
Sand Force and Mold Breaker Excadrill have pretty different checks to each other. Still, there are Pokemon that are just capable of stopping Excadrill hard no matter what it decides to bring. Skarmory and Tangrowth laugh at the likes of Swords Dance and Toxic (in the short-term). Offensive Breloom can often take one Earthquake, and just OHKO any Excadrill with Mach Punch. Fortunately, unlike other Pokemon with different sets that have different counters, Mold Breaker comes with an announcement that immediately narrows down what set Excadrill is running. Sand Force Excadrill is handily checked by Landorus-T and Slowbro and often times is outright countered by Rotom-W, Hippowdon, Gliscor, and Bronzong. The former four aught to watch out for Toxic, though, and Gliscor should activate Poison Heal early and watch out for Swords Dance Iron Head. Zapdos is also a good check, but is worn down by Stealth Rock, sandstorm, and Rock Slide too easily in addition to being vulnerable to Toxic. Choice Scarf Keldeo and Air Balloon Heatran are decent offensive checks; Latios and such can take advantage of an Excadrill Choice-locked into Earthquake. The best way to neuter Sand Force Excadrill, however, is simply to change the weather. Without a Sand Force boost, all of the aforementioned checks become counters.
Mold Breaker Excadrill, while having markedly less offensive potential, just straight up knocks out Rotom-W and Bronzong while Toxic-stalling the likes of Latios and Zapdos (the former of which takes a large amount from Earthquake anyway). Gliscor and Poison Heal Breloom make decent counters, although it is not very productive to look for a direct answer as more often than not that set aims to support its team by removing hazards. This is a difficult task for most spinblockers- Gengar, for example, is cleanly OHKOed by Earthquake. Jellicent is probably the best spinblocker to confront it with, although it should be careful of Toxic. While it can't switch in on that or a boosted Earthquake and risk losing, Jellicent resists Iron Head and can utilize Will-O-Wisp to neuter Excadrill for good. Sableye does the same to an extent. It can't switch in on Earthquake at all, but because of Prankster, Sableye doesn't have to take two attacks to burn Excadrill and has a Taunt fast enough to prevent Toxic and Stealth Rock. Often times it is sufficient to wear down Excadrill as it has no reliable recovery, and forcing it to switch in on powerful Draco Meteors and Hurricanes will greatly lower its survival time and limit the number of times it can Rapid Spin in a game.