Yes, Defeatist cuts both of Archeops's offensive stats if it gets below 50%, you are in fact right. As for VoltTurn, let me weigh in here too! (prepare for a really long post lol)
Mesprit @ Leftovers
Trait: Levitate
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Stealth Rock
- Psychic
- Thunderbolt / Ice Beam
- U-turn
Mesprit is a great choice to put on a VoltTurn team because of its bulk and access to U-turn. It also has access to Stealth Rock; and this is nice because hazards are excellent on VoltTurn since the U-turn/Volt Switch will enforce a lot of switching so wearing stuff down while VoltTurning is neat. Mesprit also has nice bulk so it can come in and hit decently hard, while U-turn allows it to grab momentum off the bat. Psychic and either Thunderbolt or Ice Beam provide decent coverage, and although Mesprit isn't remarkably powerful; its damage output is still decent enough to cut it. Levitate is also a great ability, so while Mesprit is constantly U-turning out, it doesn't have to worry about Spikes, which are indeed becoming rather ubiquitous. It has usable resistances to Fighting and Ground so it can come in on some attacks, and its bulk isn't that great but it's feasible. Mesprit also pairs up decently with other VoltTurn members such as Primeape and Manectric. In fact, any of Mesprit's on site sets that have U-turn can fit the bill here, I just put the SR one up for a good example.
Primeape @ Choice Scarf
Trait: Vital Spirit
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Close Combat
- Stone Edge
- U-turn
- Ice Punch
Primeape is also a good choice to put on a VoltTurn team, and despite its fall to NU, Primeape is still very viable. It's got a really nice Speed tier at 95, which is very good for a Scarfer, and it can outspeed numerous threats in the tier; especially Shell Smash Omastar, which is great because Omastar is a monster atm. It can U-turn pretty quickly, and it lures in threats like Spiritomb and Uxie, and can just U-turn right out to get in a partner like Absol or something. Primeape is also resistant to Stealth Rock, which is nice, although it still gets wrecked by Spikes. Its Close Combat is decently powerful with its usable Attack stat; it's not enough to do extreme damage, but it's pretty decent for a fast revenge killer (and it OHKOes Omastar so Primeape is feasible as an Oma check). Stone Edge and Ice Punch are just there for decent coverage against things like Scolipede and Golurk, which can comfortably come in on a Close Combat. Primeape admires hazards so it can easily do its job as both a revenge killer and fast scout, and is great on a VoltTurn team. If you're looking for something on VoltTurn, definitely give this guy a shot.
All in all, I like VoltTurn, and it's really good in conjunction with Spikes and Stealth Rock to chip down opponents between Volt Switch and U-turn, and can break some defensive cores, and get something to clean up later. Speaking of hazards, that brings me to this.
Spikes
Spikes are really good in the current metagame imo. While Stealth Rock is often better, Spikes can easily chip off a whopping 1/4 of each Pokemon's health upon their entry, which is really nice. This means some walls like Steelix and Spiritomb will get defeated more easily, and many Pokemon dislike Spikes because it cuts their lifespan much more quickly. There are plenty of Spikes users available, and here's two I've been taking a liking to lately.
Scolipede @ Life Orb
Trait: Swarm
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Spikes
- Megahorn
- Earthquake
- Rock Slide / Toxic Spikes
Fast spiking is something I like, and Scolipede is pretty awesome at the job. It's not as good as Smeargle, obviously, but Scolipede definitely has its perks. Aside from the fact that Scolipede is 100% manly, it's pretty fast, and is faster than most of the metagame, and can quickly set up Spikes. LO Spikes has been one of my favorite Scolipede sets so far; it's really consistent. It sets up hazards, but Scolipede also hits pretty decently hard with LO Megahorn, along with QuakeSlide coverage to back it up, so it also poses a very strong offensive threat on its own. Bug STAB is also pretty good to have atm, hitting a good portion of the tier for good damage. Overall this has been a very consistent spiker for me when I need it.
Roselia @ Eviolite
Trait: Natural Cure
EVs: 252 HP / 4 Def / 252 SpD
Calm Nature
- Spikes
- Giga Drain
- Sludge Bomb
- Synthesis / Toxic Spikes
Roselia is really good in RU atm, and it's kinda disappointing that it managed to drop to NU imo. It checks a lot of special threats like Galvantula, Sceptile, Omastar, Lilligant, and Rotom-C, and hence gets plenty of opportunities to get Spikes up. In general it's also a good special wall, handling those special threats and supporting its team with Spikes, or maybe Toxic Spikes if you're up for it. It's also got a decent Special Attack and usable STABs, so it also poses a threat to the thing's it's supposed to. It's pretty physically frail and is bad at escaping Pursuit from Escavalier and Spiritomb, and its physical fraility does hold it back some. Nonetheless, Roselia is a pretty good spiker and is decent for a bulky one (if Qwilfish isn't your cup of tea, that is).
So what do you think about Spikes and how they impact the tier? What are your favorite choices for a Spiker?