Multi Battle

Like its counterpart in Pokémon X & Y, the Battle Maison includes the special Multi Battle mode. Here, you can participate in Double Battles against two trainers, selecting two of your Pokémon. When you begin, you first get asked if you wish to do this with a friend. This is done via local connections, starting with utilising the 3DS IR and allows for you to both challenge it at the same time. Your streak is reset if you do this.

However, if you don't wish to play with a friend locally, you can play with an AI player. This time, unlike Pokémon X & Y, you have a limited amount of options, limited to your rival, Wally, Maxie/Archie and Steven, with no option for using the players on your friend list. This time, however, several of these characters have Mega Evolutions to help give you a further boost

Rival Partner's Pokémon

Pokémon Trainer Brendan
Pokémon Trainer May
 
Claydol

Levitate
Attacks:
Light Screen
Reflect
Earth Power
Psychic
Hold Item:

Light Clay
Exploud

Soundproof
Attacks:
Hyper Voice
Fire Blast
Blizzard
Shadow Ball
Hold Item:

Assault Vest
Pokémon Trainer Wally 
Gallade

Steadfast
Attacks:
Psycho Cut
Close Combat
Leaf Blade
Swords Dance
Hold Item:

Galladite
Magnezone

Magnet Pull
Attacks:
Thunder Wave
Thunder
Reflect
Flash Cannon
Hold Item:

Air Balloon
Pokémon Trainer Maxie 
Camerupt

Magma Armor
Attacks:
Earth Power
Fire Blast
Flash Cannon
Yawn
Hold Item:

Cameruptite
Crobat

Inner Focus
Attacks:
Cross Poison
Brave Bird
Super Fang
Roost
Hold Item:

Life Orb
Pokémon Trainer Archie 
Sharpedo

Rough Skin
Attacks:
Crunch
Aqua Jet
Poison Fang
Waterfall
Hold Item:

Sharpedonite
Crobat

Inner Focus
Attacks:
Cross Poison
Brave Bird
Super Fang
Roost
Hold Item:

Life Orb
Pokémon Trainer Steven 
Aerodactyl

Rock Head
Attacks:
Rock Slide
Ice Fang
Thunder Fang
Fire Fang
Hold Item:

Focus Sash
Metagross

Clear Body
Attacks:
Meteor Mash
Bullet Punch
Zen Headbutt
Hammer Arm
Hold Item:

Metagrossite