Other XY Dark Monotyope RMT

[ASmogonNameForSmogon]

Greninja @ Life Orb
Ability: Protean
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
- Hidden Power [Fire]
- Ice Beam
- Extrasensory
- Scald

Greninja is my special sweeper being one of the biggest checks to dark mono's threats. Extrasensory and Hidden Power Fire help to deal with Dark's weaknesses. The reason I chose Scald instead of moves like Water Shuriken is because I needed Greninja to be Special and Scald's Burn is also helpful.Other than those I just use Ice Beam to sweep.

Umbreon @ Leftovers
Ability: Synchronize
EVs: 252 HP / 4 Def / 252 SpD
Sassy Nature
- Moonlight
- Toxic
- Confuse Ray
- Foul Play

Umbreon a great wall with being pure Dark and with access to Moonlight and Toxic, he can also stall quite well. I also didn't choose another STAB because I want Umbreon to be more support-based. I also gave him Foul Play in case of Taunt and to finish off physical sweepers.

Bisharp @ Focus Sash
Ability: Defiant
EVs: 252 Atk / 4 Def / 252 Spe
Adamant Nature
- Knock Off
- Sucker Punch
- Swords Dance
- Iron Head

Bisharp's my secondary physical sweeper with Knock Off and Sucker Punch as STAB and Iron Head mainly to get rid of Fairies. The Focus Sash is to help him survive that 4x weakness to fighting. I wanted to give him a Fighting-type move because of the high amount of Normal-type monos but I settled with Iron Head for type coverage. He also needs Swords Dance because he's too weak to sweep without a set-up.

Mandibuzz @ Rocky Helmet
Ability: Overcoat
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
- Brave Bird
- Toxic
- Roost
- Defog

Mandibuzz is another great staller with being neutral against Bug and Fighting-types and having Super Effective STABs against both of them.
It gets Roost so it can stall longer and survive Brave Bird's recoil, I chose Brave Bird over other Flying-type moves like Aerial Ace because I wanted to KO Bug or Fighting-types in one hit and take recoil than spam a low-power move and take a lot of damage from the opponent. I chose Defog instead of another STAB as it gets rid of Rocks/Spikes while clearing statuses instead of just clearing statuses with Umbreon's Heal Bell.

Hydreigon @ Assault Vest
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Mild Nature
- Dragon Pulse
- Dark Pulse
- Charge Beam
- Earth Power

Hydreigon's a good special sweeper with Assault Vest for some bulk since it'll only use damaging moves anyway and that 4x Fairy weakness needs help. I gave it Dragon and Dark Pulse for STAB, Charge Beam to set-up while dealing damage and Earth Pulse because I've seen it be handy against Lucario. I chose Charge Beam iver other moves because it also ups Hydreigon's Special Attack while dealing damage and was also the only way to set him up with an Assault Vest.

Tyranitar-Mega @ Tyranitarite
Ability: Sand Stream
EVs: 4 HP / 252 Atk / 252 Spe
Hasty Nature
- Crunch
- Earthquake
- Dragon Dance
- Stone Edge

Tyranitar's my mega and physical sweeper. His Sand Stream ability and the stalls' Toxic gave good synergy. I chose Tyranitar over Absol-Mega because I needed to balance the team with a physical sweeper and I preferred his Sand Stream Ability. I chose Earthquake over Fire/Ice Punch because of the higher power, Greninja's Scald and Ice Beam can deal the same status effects and Earthquake still does 2x damage on Steel-types.

Edit: Thought Defog removed statuses, fixed it.

 

[Quad9]

Seems like a nice balance. What do you have for Infernape or Breloom though? Mandibuzz? I have found these to be extremely dangerous threats to my mono dark. Infernape was particularly devastating for me as anything it couldn't throw close combats at before their turn would be mach punched, or in the case of things like Spiritomb or Sableye, they can't do much too it. I've found both, probably more often the Breloom with sashes too.