Volcanion at Leftovers
Ability: Water Absorb
EVs: 252 HP / 252 SpA / 4 Spe
Modest Nature
- Steam Eruption
- Fire Blast
- Sludge Bomb
- Hidden Power Ice
If you're running 4 attacking moves I'd recommend an assault vest over leftovers. It can live things like a mega manectric's thunderbolt with max HP and no sp.def investment. Or even a +2 serperior's leaf storm. Specs and scarf sets are fun too.
252 SpA Mega Manectric Thunderbolt vs. 252 HP / 0 SpD Assault Vest Volcanion: 222-264 (60.9 - 72.5%) -- guaranteed 2HKO
+2 252 SpA Life Orb Serperior Leaf Storm vs. 252 HP / 0 SpD Assault Vest Volcanion: 278-329 (76.3 - 90.3%) -- guaranteed 2HKO
Anyway, about Volcanion:
+ Y'now how everyone argues over whether or not scald is broken and needs to be banned? Steam eruption is a bit more broken than scald, with 30 more base power although it will miss sometimes with 955% accuracy
+ Water absorb is its only ability, but its a decent one, letting volcanion heal instead of being hit with a water move. Its a shame it can't balance it with another immunity ability like lanturn though
+ A massive movepool, special and physical moves including fire, water, poison, ground, fighting and steel moves. It even gets explosion.
+ A solid 130 special attack can do tons of damage, and 120 Attack completes a mixed sweeper
+ 120 defence is pretty nice, and its not exactly frail from the special side.
+ Gets substitute, but is often outsped by stuff that would status it
+ 110 Physical attack makes a big explosion
- Lacks support and boosting moves besides flame charge, can sometimes need a baton passer to back it up
- No physical water moves makes it difficult to run a purely physical set
- 70 speed isn't great. Even max speed timid its slower than mega aerodactyl and mega manectric. You might even want to see if you can consider if your set will handle certain venusaurs and magnezones.
- key weaknesses to stealth rocks and vulnerability to spikes and toxic spikes
Volcanion @ Life Orb
Ability: Water Absorb
EVs: 220 Atk / 252 SpA / 36 Spe
Naive Nature
- Flame Charge
- Steam Eruption
- Sludge Bomb
- Explosion
Anyway, this is a set that uses flame charge to get to +1 then sweep hard, then when its nearing the end due to residual damage, priority moves, life orb etc, go boom with explosion. At +1 Volcanion and with these EVs volcanion can outspeed Max Speed Jolly Excadrill and adamant mega lopunny. It also hits hard with both special and physical attacks.
Countering Volcanion
Volcanion hits hard, but that's about all it does, it doesn't set up and rarely uses status moves. So
a really effective special wall such as Chansey is your best bet. However be careful as even bulky sweepers like Assault Vest Serperior will stuggle to live supereffective specs attacks from that titanic 130 special attack, most pokemon will take massive damage from something Volcanion can do. Its also weak to powerful special moves unless its wearing assault vest, leaving it vulnerable to mega manectric and serperior. Unless volcanion specs, Mega Tyranitar lives a steam eruption well in the sand and hits hard back with stone edge. The rare Pokemon that carry protect in singles such as gliscor can also be useful since they can check what volcanion is locked into. Basically if you want something that lives choice specs supereffective hits, tough luck. You're best bet is to take advantage of the choice item Volcanion usually holds and force it to switch out, and wear it down a lot with stealth rocks before hitting it hard with one of the several type weaknesses volcanion had.