Wynaut, here's my team for singles in World Tournament:
~252 HP, 252 Defense
-Will o wisp
This Sableye can stall out and set up on a lot of Pokemon. It can tank from both sides thanks to Calm Mind and Will o wisp, and also has an immunity to a good amount of attacks. After a few Calm Minds, Dark Pulse hits fairly hard. The main weakness of this Sableye is Pokemon with Guts, Pokemon with Toxic and sleep moves, Fire types, and special attackers that hit very hard. Will o wisp's unreliable accuracy is also an issue.
Because entry hazards are very uncommon here, it's safe to run a focus sash. I chose it over scarf since there's some Pokemon it can copy that suck if they're locked into one move. I mostly have it to counter set up Pokemon, and it's fun to use as well.
~252 Attack, 252 Speed
A last resort cleaner that can go in if Sableye is taken out. It outspeeds pretty much everything thanks to Speed Boost, and hits pretty hard hard with that attack stat.
In rotations and doubles, I add this Hydreigon.
~Dragon Fang (I'll probably replace it soon)
~252 Sp. Attack, 252 Speed
Hydreigon is capable of OHKOing most Pokemon with its attacks, which would be even more dangerous if I got a better item for it. It outruns most opposing Pokemon, which is good. I might replace Surf since it can't be used in doubles well with this team.
Also, in doubles, I replace Sableye with this Hitmontop:
~252 Attack, 252 HP
-Hi Jump Kick
A useful Hitmontop to use in doubles. It hits hard, can flinch the first turn, and has priority in Mach Punch, and can lower opposing attack power with Intimidate. It has a huge problem with Ghost types, though, so I may replace one of the moves with a coverage attack.
No team for triples yet.