Kyogre - It gets two very strong moves that bit both opponents, Origin Pulse and Water Spout. High special attack and rain ability boosts them even higher. I would recommend Ice Ben and Thunder as the other moves. With a spread with 252 SpAtt, and the rest in HP and speed, its a great doubles Pokemon. I recommend a Modest nature.
Groudon - Same reason as Kyogre. A very good mixed attacker as well as physical. Can run Eruption. Precipe Blades. Solar Beam and Stone Edge on mixed (either naive and 252 att 4 spatt 252 speed or adamant 252 att 252 HP 4 speed or speed for a set like this: Precipe Blades, Fire Punch, Swords Dance and protect\thunder punch)
Xerneas - Very good Pokemon. Dazzling Gleam hits both opponents. Geomancy raises stats. Can run Moonblast or protect or focus blast or Thunderbolt finally. I'd recommend 4 HP 252 SpAtt 252 Speed Timid or 252 HP 252 SpAtt 4 Speed.
Rayquaza - Gotta be on there. Good mixed attacker with Dragon Ascent Earth Power Extreme Speed Draco Meteor. 252 attack 4 SpAtt 252 Speed Hasty. Can also run physical: Dragon Ascent Extreme Speed Swords Dance Waterfall. 4 HP 252 attack 252 Speed jolly.
Yvetal - great support Pokemon. With knock off snarl oblivion wing tailwind, it can support. I recommend a timid nature 4 SpAtt 252 HP 252 Speed. Offended is also usable. Oblivion Wing Dark Pulse Heat Wave Sucker Punch 4 attack 252 SpAtt 252 Speed hasty.
Lunala is epic speed control. Trick Room Tailwind and icy wind are available. I didn't include it as you didn't want trick room.
Hope I helped!