Articuno @ Never-Melt Ice  
IVs: 14 HP / 24 Atk / 26 Def  
- Blizzard  
- Hidden Power [Flying]  
- Ice Beam  
- Reflect  

Jolteon @ Mint Berry  
- Curse  
- Growth  
- Rest  
- Thunderbolt  

Marowak (M) @ Thick Club  
- Screech  
- Bonemerang  
- Icy Wind  
- Submission

Articuno beats Marowak, Ursaring, and Grass types. Reflect can be used to halve damage from hard hitting physical attackers such as Ursaring and Heracross. HP Flying 3hkos Jynx and hits Fighting-types.
Jolteon beats Blissey, Alakazam, Jynx, and Water types. Curse lets Jolteon set up Growth on other Curse users lacking Earthquake.
Marowak covers Articuno's weaknesses very well, beating Machamp, Heracross, and Tyranitar (icy wind into submission) along with Fire, Electric, and Ghost types.