I have a passionate hatred for choice items this meta, just because diversity is essential. My team [unbeaten so far]:
Scizor @ Leftovers
Flash Fire
-Magic Coat
-U-Turn
-Toxic Spikes
-Stealth Rock
Such an awesome lead. Mirror coat deals with any deoxys that doesn't use quiver dance, once they're sleeping you're free to either set up (vs non-magic guard) or switch to Contrary Dialga. Flash fire means no weaknesses and often surprises opposition unless they trace it.
Giratina @ Leftovers
Magic Bounce
-Heart Swap
-Dragon Tail
-Toxic Spikes
-Rapid Spin
Whilst it isn't often that people manage to set up vs this team, it's always good having a spinner. If you play scizor correctly then you should have 2 tspikes and some rocks whilst they have nothing, so just uturn out to this guy and dragon tail rape his entire team. Heart Swap there for any contrary users Blissey hasn't taken care of, also deals with Moody pokes.
Dialga @ Lum Berry
Contrary
-Draco Meteor
-Leaf Storm
-Substitute
-V-Crete
Best contrary user. Get the sub up (lum berry should deal with any status ect), V-Crete for the obvious speed boost initially, then just ruin everything with draco meteor. Leaf storm is for covering Groundon/Kyogre, who were previously problematic. Swept so many teams with this guy it's unreal.
Lugia @ Leftovers
Prankster
-Magic Coat
-Whirlwind
-Spikes
-Substitute
Everyone hates playing versus this guy. Genuinely the most annoying poke out there, with good reason. Magic Coat deals with all the status problems (requires good prediction though). Sub for immunity in case you happen to whirlwind into a contrary user, then spikes as an additional entry hazard in case they managed to spin the initial ones away and have a shedinja on their team.
Slaking @ Leftovers
Magic Bounce
-Sacred Fire
-Extreemespeed
-Swords Dance
-Earthquake
Standard slaking. Trick is to only SD once, otherwise if they have an imposterblissey you're pretty much screwed. I designed this set so that if it's taken, it can be walled by Heart Swap Giratina (SD EQ only does like 42%). Magic Bounce is a nice touch given deoxys often tries to spore this guy.
Blissey @ Leftovers
Imposter
-Protect
-Toxic
-Wish
-Will-o-wisp
Standard imposterbliss, ruins the life of anything using contrary.