Trubbish @ Eviolite
Ability: Sticky Hold
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
- Spikes
- Toxic Spikes  / Drain Punch
- Gunk Shot
- Pain Split
Fun mon to be used in stalls and hard 
walls our victim. Uses FairyVally to set up hazards and can 2HKO Vally with gunk shot (LOL, IKR). Eviolite will stick with you thanks to the sticky hold. Drain punch can be used to punish plausable u-turn switches like a-slash. Pain split keeps the Trubbish healthy during the game, thanks to its massive base 50hp stat and can punish your oppo that way too.
The cute dmg:
252 Atk Silvally-Fairy Multi-Attack vs. 252 HP / 252+ Def Eviolite Trubbish: 38-45 (12.5 - 14.8%) -- possible 
7HKO 
+6 252 Atk Silvally-Fairy Multi-Attack vs. 252 HP / 252+ Def Eviolite Trubbish: 153-180 (50.3 - 59.2%) -- guaranteed 2HKO
The not-so cute dmg:
0 Atk Trubbish Gunk Shot vs. 4 HP / 0 Def Silvally-Fairy: 156-186 (46.9 - 56%) -- 76.6% chance to 2HKO
Enjoy,
Lets see how long it will take for Oathkeepre to snipe me with this, the clock starts now!
EDIT :(
SO;
Haunter @ Choice Scarf 
Ability: Levitate 
EVs: 252 SpA / 4 SpD / 252 Spe 
Timid Nature 
IVs: 0 Atk 
- Sludge Wave 
- Shadow Ball 
- Destiny Bond 
- Trick
252 SpA Haunter Sludge Wave vs. 4 HP / 0 SpD Silvally-Fairy: 300-354 (90.3 - 106.6%) -- 37.5% chance to OHKO
This
 kills silvally fairy, end of story :( ps. go for modest if u want a clean OHKO (but it lives a hit from silvally without problem)
Checkedi check