Don't know if some of these have been posted, but I'll put ones below that I think I either came up with, used in a notable game or had recommended to me that I enjoy using.
Cobalion @ Lum Berry
Ability: Justified
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Close Combat
- Iron Head
- Rock Polish
Double Dance Cobalion I used a lot before Zapdos drop. It got worse at that juncture, which coincided with FatMence becoming more popular, so Edge became a great option. It's gotten better now, with chip damage on Sableye you can kill it with +2 Iron Head.
Ability: Justified
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Close Combat
- Iron Head
- Rock Polish
Double Dance Cobalion I used a lot before Zapdos drop. It got worse at that juncture, which coincided with FatMence becoming more popular, so Edge became a great option. It's gotten better now, with chip damage on Sableye you can kill it with +2 Iron Head.
Reuniclus @ Leftovers
Ability: Magic Guard
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Calm Mind
- Acid Armor
- Psyshock
- Recover
There's definitely a more optimal EV spread for this, but used in tandem with TSpikes it lets you wear down Krook or other Knock users typically so you can win 1v1 barring a crit. Hydrei remains a problem but things like Entei becomes less of a check against you.
Ability: Magic Guard
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Calm Mind
- Acid Armor
- Psyshock
- Recover
There's definitely a more optimal EV spread for this, but used in tandem with TSpikes it lets you wear down Krook or other Knock users typically so you can win 1v1 barring a crit. Hydrei remains a problem but things like Entei becomes less of a check against you.
Haxorus @ Mental Herb
Ability: Mold Breaker
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Dragon Dance
- Outrage
- Poison Jab
- Earthquake
Ada +1 outspeeds MAero which was always a fine benchmark for me, others might want jolly though. If Ada you can use Dragon Claw > Outrage if you want. Use this against people who rely on Whimsicott as a general dragon check, they will often feel safe bringing it in on/after an EQ or DD to Encore.
Ability: Mold Breaker
EVs: 252 Atk / 4 SpD / 252 Spe
Adamant Nature
- Dragon Dance
- Outrage
- Poison Jab
- Earthquake
Ada +1 outspeeds MAero which was always a fine benchmark for me, others might want jolly though. If Ada you can use Dragon Claw > Outrage if you want. Use this against people who rely on Whimsicott as a general dragon check, they will often feel safe bringing it in on/after an EQ or DD to Encore.
Amoonguss @ Life Orb
Ability: Regenerator
EVs: 248 HP / 252 SpA / 8 SpD
Modest Nature
- Spore
- Giga Drain
- Sludge Bomb
- Hidden Power [Fire]
LO Amoonguss hits fairly hard, I love having 100% sleep on a relatively offensive mon, HP Fire is a great lure for Escav which is rising in popularity because typically Escav deals with every variant of Amoonguss
Ability: Regenerator
EVs: 248 HP / 252 SpA / 8 SpD
Modest Nature
- Spore
- Giga Drain
- Sludge Bomb
- Hidden Power [Fire]
LO Amoonguss hits fairly hard, I love having 100% sleep on a relatively offensive mon, HP Fire is a great lure for Escav which is rising in popularity because typically Escav deals with every variant of Amoonguss
Xatu @ Leftovers
Ability: Magic Bounce
EVs: 252 HP / 252 Def / 4 SpA
Bold Nature
IVs: 0 Atk
- Roost
- Toxic
- Calm Mind
- Psyshock
Use this against people who enjoy stall, it 1v1s Sableye/Whims basically anything that relies on a status move to beat you. EV spread is, again, probably not optimal so play around with that. Setup sweepers that are good vs Tenta and Milo are nice because they have to take an unnecessary move to haze them. Pair with Pursuit to gradually weaken MAero because that is on stall a bit, also need a good steel check because things like Escav are a pain
Ability: Magic Bounce
EVs: 252 HP / 252 Def / 4 SpA
Bold Nature
IVs: 0 Atk
- Roost
- Toxic
- Calm Mind
- Psyshock
Use this against people who enjoy stall, it 1v1s Sableye/Whims basically anything that relies on a status move to beat you. EV spread is, again, probably not optimal so play around with that. Setup sweepers that are good vs Tenta and Milo are nice because they have to take an unnecessary move to haze them. Pair with Pursuit to gradually weaken MAero because that is on stall a bit, also need a good steel check because things like Escav are a pain