Ok, refined the Tapunium Koko set.
"Tapunium Koko"
Tapu Koko @ Tapunium Z
Ability: Electric Surge
EVs: 252 Atk / 4 SpA / 252 Spe
Hasty Nature
- Wild Charge
- Brave Bird
- Hidden Power [Ice]
- Nature's Madness
Tapu Koko is probably the only really good Nature's Madness user. While it may seem like an un-intuitive move for a sweeper to have, it actually serves a few purposes. Even without Tapunium-Z it makes a great scouting move, to soften up switch-in's and counters. If you know your damage calcs, you can just about 2HKO any switch in with NM or NM-Z plus one of its standard attacks. Think about it this way, any Wall that tries to come in and shut you down, you only need to be able to do 25-31% to it to KO. And 130 base speed with a +speed nature means you are definitely getting your attack in on even other fast switch-ins that try to take advantage of absorbing electric attacks with ground. Just bewear (pun) for Choice Scarf users.
Some calcs vs common switch-ins:
252 Atk Tapu Koko Wild Charge vs. 252 HP / 0 Def Aegislash-Shield in Electric Terrain: 76-90 (45.5 - 53.8%) -- 37.9% chance to 2HKO
4 SpA Tapu Koko Hidden Power Ice vs. 248 HP / 0 SpD Gliscor: 112-136 (61.8 - 75.1%) -- guaranteed 2HKO after Poison Heal
4 SpA Tapu Koko Hidden Power Ice vs. 0 HP / 4 SpD Garchomp: 100-120 (54.6 - 65.5%) -- guaranteed 2HKO
252 Atk Tapu Koko Wild Charge vs. 252 HP / 252+ Def Eviolite Chansey in Electric Terrain: 138-163 (38.6 - 45.6%) -- guaranteed 3HKO
252 Atk Tapu Koko Brave Bird vs. 0 HP / 0 Def Mamoswine: 76-90 (41 - 48.6%) -- guaranteed 3HKO
252 Atk Tapu Koko Brave Bird vs. 252 HP / 4 Def Tapu Bulu: 112-132 (63.2 - 74.5%) -- guaranteed 2HKO
While those numbers don't look initially very impressive, After a Nature's Madness or Guardian of Alola when the switch-in is expecting a resisted hit, you now outspeed and OHKO, removing Tapu Koko's primary counter. A lot of these threats don't even need Z-Boosted Nature's Madness, so you can even save it for a final gambit for later in the match.
This brings me to the second use for Nature's Madness: recoil reduction. In the scenarios above, you are doing 50-75% off the bat meaning your Wild Charge/Brave Bird recoil isn't taking nearly the same toll on your sweeper as it would have otherwise. And given Koko is actually not super frail, you can potentially survive a hit and do it again making this a 2-1 or 3-1 mon. On less-threatening opponents that you can't OHKO anyway, Nature's Madness followed by a standard attack again mitigates the toll sweeping takes on Tapu Koko.
And lastly, if you are on your last legs, and you don't have a switch-in for the current threat, Nature's Madness or Guardian of Alola on your way out means Tapu Koko won't ever be just a sacrifice -mon.
Mamoswine and Mudsdale are great offensive partners for Tapu Koko, ignoring electirc attacks your opponent might throw out to take advantage of your electric terrain and have the bulk and prowess to finish off mons that take Koko down after Nature's Madness. Priority users also do a great job as they perform best taking out already weakened mons. Pyukumuku is also a fantastic partner for Koko due to Soak and a slow baton pass, creating weaknesses which will invoke switches once you bring Koko in.
