Hey I'm posting this team because I'm hoping to get good feedback and better my teambuilding.  This team is illegal because skymin is banned (even though as stated in the post the team is only 1000 pbv :< ) so everything here is just theorymon atm.

Intuition #Centered
I started off with Wartortle.  I saw it on the ladder a couple of times and wanted to see if I could use it on a team.  After looking at the analysis set in the dex I decided to go with a physically defensive set. Wartortle checked some mons that were annoying to lo Skymin like Blaziken and Talonflame.  So, I tried to see if I could build around Wartortle and Skymin (at the time I didn't know that it was banned). Since Skymin was on the team, the remaining mons must have low pbvs (the average would have to be 141.25pbv).  Obviously I would need something for Thundurus and Zard-Y as well as another physical wall that could take knock offs.  I used Mega Aggron for the other physical wall and Goodra as the Thundurus and Zard-y switchin.  A cleric was another thing I wanted (I didn't have a status absorber and I was planning on running rest on wartortle), so I decided to use a poke I tend to use a lot - spdef Sylveon (it's cheap and checks a decent number of offensive support mons).    At this point the team looked a little sand weak and I wanted a mon to pursuit trap mega gar and potential spinblockers.  I remembered a friend used physically defensive Krookodile on his Mega Venusaur semi stall team to help with sand offense.  Its pbv was low enough so I decided to go for it.  I needed to run an av though to live a Focus Blast from Mega Gengar.


The Team #Centered
https://media.pokebattle.com/pksprites/front/008.gif
Wartortle @ Eviolite
Ability: Torrent
EVs: 252 HP / 252 Def / 4 SAtk
Bold nature
- Scald
- Rapid Spin
- Rest
- Toxic

Wartortle was the mon this team was built around.  It's a bulky water that spins for Shaymin-s.  The ev spread is designed to aid it in checking Blaziken, Talonflame, and non Freeze-Dry Mamoswine.  The moves are pretty standard: Scald, Rapid Spin, and Toxic because Wartortle is a bulky water that spins.  Rest is to help it from getting worn down too quickly.


https://media.pokebattle.com/pksprites/front/492-sky.gif
Shaymin-S @ Life Orb
Ability: Serene Grace
EVs: 4 Def / 252 SAtk / 252 Spe
Timid nature
- Air Slash
- Seed Flare
- Earth Power
- Leech Seed

Shaymin-Sky is the reason this team could work.  Skymin acts as a breaker for the team and is usually this team's wincon.  The ev spread is pretty straightforward - max speed, max spatk, and 4 def evs (the HP number is odd so as to minimize damage from rocks).  Life Orb to maximize damage output w/o getting choice locked.  Seed Flare, Air Slash, and Earth Power are standard moves.  Leech Seed acts as a form of recovery.


http://www.pkparaiso.com/imagenes/xy/sprites/animados/aggron-mega.gif
Aggron @ Aggronite
Ability: Sturdy
EVs: 252 HP / 16 Def / 240 SDef
Relaxed nature
- Stealth Rock
- Ice Punch
- Iron Head
- Fire Punch

Mega Aggron tanks a lot of physical attacks.  It sets up rocks and messes with teams that rely on gothitelle to kill Stealth Rock users.  The evs look a little weird at first glance but Mega Aggron has so much defense that adding more to it doesn't really help, so it is invested in spdef, the 16 def evs give a "jump point".  The moveset is fairly standard for a tank set.  Stealth Rock is there because rocks are awesome.  Iron Head is stab. Ice Punch is there to hit ground types (eg lando-t and gliscor) on the switchin and Fire Punch hits Mega Scizor and Ferrothorn which are otherwise fairly annoying for this team.


https://media.pokebattle.com/pksprites/front/706.gif
Goodra @ Assault Vest
Ability: Sap Sipper
EVs: 248 HP / 160 SAtk / 8 SDef / 92 Spe
Calm nature
- Thunderbolt
- Sludge Wave
- Draco Meteor
- Fire Blast

Goodra is meant to be a spdef tank.  It counters Zard-Y and Thundurus.  The evs have the same amount of special bulk as listed in the dex analysis, but I run a bit more speed to creep jolly Azumarill and put the rest in spatk.  The moveset's a bit odd.  Right now I have Draco Meteor for STAB, Thunderbolt for bulky waters, and Fire Blast and Sludge Wave for coverage.


https://media.pokebattle.com/pksprites/front/700.gif
Sylveon @ Leftovers
Ability: Pixilate
EVs: 252 HP / 4 SAtk / 252 SDef
Calm nature
- Hyper Voice
- Wish
- Heal Bell
- Protect

Sylveon's a convenient cleric that I tend to use on a lot of my teams.  The evs maximize spdef.  Origianlly, I thought a mixed set might work better, but I didn't find it useful.  The moveset is standard for cleric Sylveon.


https://media.pokebattle.com/pksprites/front/553.gif
Krookodile @ Assault Vest
Ability: Intimidate
EVs: 248 HP / 200 Def / 60 SDef
Impish nature
- Knock Off
- Earthquake
- Pursuit
- Stone Edge

Krookodile acts as a sort of glue to this team.  With the given evs Charizard-X's dragon claw is a 3hko after a DD, Life Orb Aegis has only a 6.3% chance to 2hko with flash cannon and a 1.2% chance with sacred sword, +2  lo exca misses the ohko, and mega gar's Focus Blast misses the ohko.  The moveset is pretty standard - Earthquake and Knock Off are STAB, Pursuit is to (potentially) pursuit trap spin blockers and Mega Gengar, and Stone Edge is coverage.