The combination of Choice Specs Tapu Koko and Spikes Skarmory is very potent right now.
+ 
This combination works because of the excellent synergy of Spikes + Tapu Koko. Tapu Koko has three categories of defensive checks: Ground types, bulky Grass types, and Blissey/Chansey.
Ground types all present opportunities for Skarmory to come in and lay down spikes. Ground types do not tend to run boots currently, and the one Spikes-immune ground, Lando-T, gets annihilated by Specs Dazzling Gleam AND lets Skarmory lay more spikes.
Bulky Grass types basically means Ferrothorn, because AV Tangrowth doesn't exist on the ladder right now. Ferrothorn is more annoying, because you trade Spikes with Skarmory, but it still is greatly weakened from having to come in on Volt Switch + Spikes. Body Press on Skarmory allows you to sort of win the 1v1.
Blissey runs boots, and so is not concerned with Spikes. However, Blissey is an invitation to click Volt Switch and go out to your Blissey answer, giving you lots of momentum.
The other important benefit is that Tapu Koko beats like almost every defogger. If your opponent has a defogger that isn't Lando-T, every time they want to defog is an invitation for Koko to come in. The major problem with this core is that Tapu Koko gets worn down quickly. I think using last move Roost is a good way to mitigate this, but it can be a large momentum sink. I've also experimented with last move Toxic or Grass Knot, but I think that Roost is the best option.
Set Notes
I have been using Modest Tapu Koko, which was a big no-no in Gen7, but it works because there is a big hole in the speed tiers. I would consider changing it to Timid for Cinderace, but the extra power is very nice, and especially with the terrain nerf, Koko needs all the power it can get. Modest isn't necessary, but if you're all about power like I am, you should give it a whirl.
Ladder players often will bring teams that are mono-walled by Skarmory, and it's especially fun to see +2 LO Garchomp Scale Shot completely bounce off. Whirlwind is necessary on this set so you don't lose to SD Fire Fang Garchomp or something stupid like that, but Body Press can be whatever you like. I like Body Press to beat Ferrothorn, but Brave Bird or Iron Head could work. Absolutely do not use SpDef Skarmory here, because you need Skarmory to actually beat physical attackers.


Skarmory @ Rocky Helmet
Ability: Sturdy
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Roost
- Spikes
- Whirlwind
- Body Press
Tapu Koko @ Choice Specs
Ability: Electric Surge
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
IVs: 0 Atk
- Toxic/Grass Knot/Roost/Whatever
- Thunderbolt
- Dazzling Gleam
- Volt Switch
Ability: Sturdy
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Roost
- Spikes
- Whirlwind
- Body Press
Tapu Koko @ Choice Specs
Ability: Electric Surge
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
IVs: 0 Atk
- Toxic/Grass Knot/Roost/Whatever
- Thunderbolt
- Dazzling Gleam
- Volt Switch
This combination works because of the excellent synergy of Spikes + Tapu Koko. Tapu Koko has three categories of defensive checks: Ground types, bulky Grass types, and Blissey/Chansey.
Ground types all present opportunities for Skarmory to come in and lay down spikes. Ground types do not tend to run boots currently, and the one Spikes-immune ground, Lando-T, gets annihilated by Specs Dazzling Gleam AND lets Skarmory lay more spikes.
Bulky Grass types basically means Ferrothorn, because AV Tangrowth doesn't exist on the ladder right now. Ferrothorn is more annoying, because you trade Spikes with Skarmory, but it still is greatly weakened from having to come in on Volt Switch + Spikes. Body Press on Skarmory allows you to sort of win the 1v1.
Blissey runs boots, and so is not concerned with Spikes. However, Blissey is an invitation to click Volt Switch and go out to your Blissey answer, giving you lots of momentum.
The other important benefit is that Tapu Koko beats like almost every defogger. If your opponent has a defogger that isn't Lando-T, every time they want to defog is an invitation for Koko to come in. The major problem with this core is that Tapu Koko gets worn down quickly. I think using last move Roost is a good way to mitigate this, but it can be a large momentum sink. I've also experimented with last move Toxic or Grass Knot, but I think that Roost is the best option.
Set Notes
I have been using Modest Tapu Koko, which was a big no-no in Gen7, but it works because there is a big hole in the speed tiers. I would consider changing it to Timid for Cinderace, but the extra power is very nice, and especially with the terrain nerf, Koko needs all the power it can get. Modest isn't necessary, but if you're all about power like I am, you should give it a whirl.
Ladder players often will bring teams that are mono-walled by Skarmory, and it's especially fun to see +2 LO Garchomp Scale Shot completely bounce off. Whirlwind is necessary on this set so you don't lose to SD Fire Fang Garchomp or something stupid like that, but Body Press can be whatever you like. I like Body Press to beat Ferrothorn, but Brave Bird or Iron Head could work. Absolutely do not use SpDef Skarmory here, because you need Skarmory to actually beat physical attackers.