tl;dr - Suicide Specs Cursola + Dugtrio with Sub or Protect can trap and eliminate most contact-attackers, including problems like Dracovish that Dugtrio cannot normally kill. Both team slots have their own uses outside of this combo: Cursola with its wallbreaking power and Dugtrio with its normal trapping. Its obviously a gimmick strategy with a lot of weaknesses but some completely unique perks, and is very fun to use as long as Arena Trap stays legal.
Cursola is not very good. At all. However, I think it does have one niche in OU that leads to a very cheesy trap setup which can eliminate physical threats that a lot of teams otherwise struggle to deal with. It's pretty easy to dismiss as a gimmick (which it is) but its a gimmick with real benefits for teambuilding, and it also a lot of fun to use and doesn't lead to two dead team slots like you may assume. Trapping in general has shown to be a pretty degenerate aspect of the game, and and since I don't know how much longer Arena Trap will last, I might as well bring this up now, as it widens the pool of targets which Dugtrio unavoidably remove of the enemy team.
I have seen one other person mention this, but they were trying to use some garbage defensive set with Eject Button. That's always going to be dead weight on pretty much any OU team. Better to actually make use of Cursola's few strengths (and even its weaknesses).
Cursola @ Choice Specs
Ability: Perish Body
EVs: 252 SpA / 4 SpD / 252 Spe
Mild Nature
IVs: 0 HP / 0 Def
- Shadow Ball
- Psychic
- Ice Beam
- Giga Drain
A defensive statline of 60/50 is so terrible that its actually a better idea to tank those numbers even further to get the most out of Perish Body. With a -Def nature, 0 HP and Def IVs, and 31 Atk IVs to maximize Foul Play damage, Cursola will not live any respectable contact move. This then triggers Perish Song, and leads into the unavoidable trap. The best part about this set is that most switch-ins are a win/win whether you can live or not, and is effective even if the opponent sees the gimmick at team preview.
If there is a specially-based support like Toxapex, Pelipper, Vaporean, or Rimbombee on the field, Cursola can easily switch in and take a hit, leaving the opponent to look for switch-ins to a 640 SpA move. If you get statused in some way, Cursola absolutely doesn't care, as it has a death wish regardless, and chip damage it on it is often a good thing. Its also a prime switch-in for its child Corsola, and even some slower special attackers like Hatterene.
On the other end of the spectrum, if the opponent has a strong physical attacker like Dracovish or even a physically-based support like Ferrothorn, you can immediately send Cursola to its death. If your opponent is smart, they can see this coming from a mile away, but even if they recognize what you're trying to pull off, there may not be anything they can do. Dracovish, for instance, only uses contact moves, so if Cursola and Dugtrio are both alive, it is legitimately unable to attack without dying. For supports like Ferrothorn, it can just choose not to click Power Whip or Knock Off, but Leech Seed is recovering basically nothing and it absolutely cannot take two Shadow Balls.
And because you have no reason not to run neutral max Speed, you can even get some surprise kills just from outspeeding slow Pokemon without investment, negating the need to use Perish Body right away. 159 Speed is enough to outspace uninvested Tyaranitar by one point, and everything slower, including prime targets like Hippowdon, Gastrodon, Quagsire, Sylveon, and Toxapex. Shadow Ball is obvious STAB, Psychic chunks Pex and snipes the occasional Conkeldurr, and Ice Beam + Giga Drain is solid coverage that takes out a few of the targets mentioned above. Other options are Hydro Pump to hit Ttar harder, and Earth Power > Psychic to hit Pex and Ttar in one, though I don't like being locked into a Ground move Flying types are good switch-ins to avoid Arena Trap. As we know from Specs Dragapult, Ghost is a very spammable type right now, and in cases where the opponent either can't kill you, can't outspeed you, or switches out to avoid the trap, good coverage combined with 640 SpA is bound to leave a mark on something.
But obviously we're here for Perish Body, so let's get onto part two.
Dugtrio @ Choice Scarf
Ability: Arena Trap
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Substitute
- Earthquake
- filler
- filler
Dugtrio @ Focus Sash
Ability: Arena Trap
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Substitute
- Protect
- Earthquake
- filler
We all know what Dugtrio does; its somehow more one-dimensional than Cursola. Because the only move it really needs to function is Earthquake, both of the above sets can serve the same purpose as a normal Scarf or Sash Dugtrio, which are very valuable tools on the right build to straight up eliminate a problem Pokemon with no way to respond. The lack of counterplay to being trapped is why trapping abilities are so frequently banned, even though the Pokemon that get them are complete garbage. One downside to Dugtrio is that if it can't kill its target in one (or two, with Sash) hits, it has failed at its job. And this situation comes up a lot, given that base 100 Atk + only one reliable strong move is very lackluster, often requiring prior chip damage or a weakness to ground in order to achieve its task. But because Perish Body guarantees death in 3 turns (which Dugtrio is unaffected by), this downside is negated because Dugtrio no longer needs to Atk in order to successfully eliminate its mark. This widens your list of targets, while keeping Dugtrio's effectiveness on a normal team almost completely intact.
I have two sets here, both are very degenerate but they have their own pros and cons. Which one you use is team dependent, so I'll go over the pros and cons of each.
Choice Scarf + Substitute is such an insulting way to die, and the extra Speed widens your hit list to sub-120 Scarfers and fast Pokemon in general, even if Dugtrio takes damage from hazards beforehand. In a pinch, Scarf EQ is a half-decent response even to targets you can't trap, like weakened Dragapult. Dugtrio's health is nearly irrelevant, allowing you to Sub three times in a row and still stay alive to get a hit off when it next switches in. In general, Scarf is best on teams that would already appreciate Scarf Dug, and you can better eliminate fast targets even if hazards are up. The obvious downside is that being locked into Sub will immediately force a switch after the target faints, but Choiced Dugtrio frequently after a successful trap even in normal circumstances, as the next Pokemon will likely be able to easily take the next Earthquake (or is immune).
Focus Sash is a bit safer and more reliable but you will need to keep the Sash intact or faster targets will be able to kill Dugtrio in two turns, meaning you sacrificed two Pokemon and the target can just switch on turn 3. Rather than spamming Sub, the goal here is Protect > Sub > Protect, which means you only lose 25% of your HP, not 75%. You can also setup Stealth Rock on the Sub turn, especially if the target is going to oustpeed you and bring you down to Focus Sash. If your hazard control is strong, this set is the better choice, and its ability to possibly set up Rocks on the second turn is an extra layer of support.
So what does this combo actually do that Dugtrio normally doesn't do by itself? Below are a list of targets that a) can be trapped and b) use commonly use contact moves that can hit Ghost types, taken from the viability thread. I'll put a * by targets that Dugtrio can already reliably kill from full with EQ, given the right set. Trapping them this way, however negates Focus Sash, Shucca Berry, and Def investment that would ordinarily stop a successful trap.
Avalugg, Bisharp*, Conkeldurr, Durant, Excadrill*, Ferrothorn, Flareon*, Haxorus, Mew(?), Snorlax, Tyranitar*, Umbreon, Barraskewda (Rain or Aqua Jet stops Scarf Dug), Centiscorch* (has to hit Stone Edge), Cinderace* (U-turn stops), Copperajah, Darmanitan-G (Flare Blitz only), Dracozolt, Dracovish, Dreadnaw (Jolly + Rain stops Scarf Dug), Grimmsnarl (Taunt stops Scarf), Obstagoon
There are some threats here! In my limited time testing, the best benefit has absolutely been a foolproof way to eliminate Dracovish. Teams without a Water immunity pretty much have to sack anytime this abomination comes in already, so sacking a Pokemon meant to die anyway is no huge loss. I've also been pretty impressed with Specs Cursola in general. Its so hard to switch into that if allowed in on a double, death, or support Pokemon, you can easily get 2 kills--one from its own power and one from Perish Body. The reason its bad in OU despite immense power is that it requires a ton of support and a lot of things will kill it. With Dugtrio in the back, both of these downsides are reversed: Cursola becomes support instead of needing it and dying is actually a success state, not a failure state.
But as I said at the beginning, this is obviously a gimmick and should be treated as such. It requires two team slots which, while not useless on their own, are definitely not optimal. Any Ghost (physical Dragapult) or non-grounded target (Corviknight, Mandibuzz, Gyarados) will foil your plans, while some physical attackers simply need to click strong non-contact moves (Darmanitan, mainly).
With that in mind, this combo is very fun to play with, especially when Dracovish is on so many teams. I don't expect to see this is a tournament anytime soon, but as a ladder strat, its pretty neat and makes use of an otherwise lackluster Pokemon. Trapping tends to create unfair game states, and dying from Dugtrio just sitting there feels especially disrespectful. Enjoy it while Arena Trap lasts, and happy holidays.