Details: One of the fourteen Special Trainers you will encounter at The Battle Tree after completing certain winning streaks or as a partner in Multi Battle Mode is Grimsley. He's one of the members of the Unova Region Elite Four, specializing in Dark Type Pokemon.
Possible Pokemon:
Houndoom (Air Ballon): Flamethrower, Shadow Ball, Sludge Bomb, Will-o-wisp
Houndoom (Houndoominite): Fire Blast, Dark Pulse, Solar Beam, Sunny Day
Tyranitar (Chople Berry): Rock Slide, Crunch, Earthquake, Dragon Dance
Sharpedo (Sharpedonite): Crunch, Ice Fang, Aqua Jet, Poison Jab
Sharpedo (Focus Sash): Ice Beam, Hydro Pump, Dark Pulse, Protect
Absol (Focus Sash): Night Slash, Zen Headbutt, Sucker Punch, Play Rough
Absol (Absolite): Sucker Punch, Megahorn, Play Rough, Stone Edge
Honchkrow (Darkinium Z): Psychic, Dark Pulse, Swagger, Shadow Ball
Drapion (Scope Lens): Cross Poison, Night Slash, Fire Fang, Earthquake
Drapion (Razor Claw): Cross Poison, Night Slash, Earthquake, Swords Dance
Liepard (Red Card): Foul Play, Sucker Punch, Sand Attack, Thunder Wave
Liepard (Focus Sash): Dark Pulse, Shadow Ball, Grass Knot, Nasty Plot
Scrafty (Fightinium Z): Substitute, Payback, High Jump Kick, Focus Punch
Scrafty (Leftovers): Bulk Up, Payback, Protect, Drain Punch
Bisharp (Chople Berry): Iron Head, Night Slash, Low Sweep, Sucker Punch
Bisharp (Focus Sash): Taunt, Sucker Punch, Metal Burst, Iron Head