Gyarados + Golurk + Tyranitar
Bulky gyarados @ leftovers
Nature: Adamant
Ability: Intimidate
EV's: 156 HP , 72 ATK , 96 DEF, 184 SPE
Moves: Dragon dance , Waterfall , Bounce , Taunt
Tyranitar @ choicescarf
Nature: Hasty
Ability: Sand Stream
EV'S: 252 ATK , 252 SPE , 4 SPA
Moves: Pursuit , Stone edge , Superpower , Ice beam/fireblast
Golurk @ muscle band / life orb
Nature: Careful
Ability: Iron fist
EV'S: 252 ATK , 200 HP , 56 SPDEF
Moves: Stone edge , substitute , shadow punch , focus punch
Immunities: Electric , Ground , Fight , Psysich
Resists: Ghost , Rock , Fire , Fight , Water , Bug , Steel , Dark
Neutral to: Ice , Grass
This combo can work both as a defensive and an offensive core. Scarftar traps and pursuits all ghosts/psysichs ( namely azelf , reuniclus , latias , gengar , chandelure) as well as adding some extra damage every turn in the form of sandstorm. Tyranitars biggest letdown are his weaknesses. Golurk is immune to fight attacks , and gyarados resists it , because of this ,he is allowed to run a hasty nature with a special coverage move like ice beam or fire blast that can take out pokemon that would wall or setup on him otherwise namely gliscor , ferrothorn and scizor. His ground and water weakness are covered by gyarados , that leaves only a grass weakness wich he still can take on most of the time due to sandstorm.
Bulky gyarados is still a great pokemon in this metagame, water + flying gives very good coverage , taunt lets him beat skarmory , and some pokemon that try to set up on him . Bounce also is a handy tool to cover the grass weakness this team has. Dragon dance is added to give him more power and a chance at a sweep.
Finally Golurk is added as the glue of this combo , im not very sure about this EV's and nature , but i tried it out and it lets him beat most thunderus sets , as he can survive a +2 hp grass/ice and then ko back with stone edge. Most thunderus stay in thinking they can take him on and will die , making the way free for gyarados. Substitute is added to ease prediction in some cases , and it goes well with the focuspunch/shadowpunch combo that has flawless coverage. He can also beat skarmory 1 to 1 with focus punch , wich is a huge plus. Muscle band can fake a choicebandset , and life orb just adds a lot more power.
If you are really concerned about grass type attacks , adding a heatran to this core is very effective( im thinking about doing that myself)
Heatran @ Air balloon / Leftovers
Nature: Calm
Ability: Flash fire
EV'S: 252 HP 252 SPDEF 4 SPA
Moves: Lava plume / Fire blast , Earth power , Stealth rock , Protect/HP Grass
Heatran adds a 4x grass resist to this combo , and also adds 2 immunites more , namely poison and fire. He also adds a dragon resist(to take draco meteor) , and 4x ice resist wich can come in very handy. He can lay down SR for the team , lava plume adds a nifty burn chance and a solid fire attack , whereas fireblast adds more power. The ev's listed make sure he can survive a 252SPA 252 SPD other heatrans earth power and still be able to ko back with his own earth power. If you use air balloon ( because of item clause or something) , you can add more EV'S from SPDEF into SPA to give him more power. Protect can scout , and stall sandstorm damage , as well as giving him an extra turn of leftovers recovery. If you decided to go with air balloon , HP grass adds great coverage to take down quagsires/gastrodons whom rise in usage lately.
Because this combo forces a LOT of switches, SR/spikes/toxicspiked support can really pay off. If anyone see's some obvious mistakes in this combo , please let me now. Im using it and i havent come across anything really. Sure i loose sometimes , but thats just because im not that good of a player. Also dont pay attention to my bad english , thx :)
Shit this almost turning out a RMT or something :(