First RMT.

[Starbuck]

I've been moving stuff around in this team for a bit, but haven't reached a sixth Pokemon that I felt "clicked" with the others. Here are the first five:

1. Celebi, @Leftovers
Bold; 252 HP, 242 Def, 16 Spd
Grass Knot, Thunder Wave, Recover, Reflect

This lead is basically to scout the opponent's team while spreading paralysis and putting up Reflect. Although Celebi leads are often criticized due to the Pursuit weakness, the only user of Pursuit here that would worry me is Scizor, who's a rather uncommon lead. Common Pursuit leads (i.e. Weavile, Tyranitar, Metagross) get paralyzed then Reflected and then there's not much they can do. Celebi is also to counter Swampert, Suicune, and Gyarados, who would otherwise give this team some trouble.

2. Scizor, @Choice Band
Adamant; 252 Atk, 252 Spd, 6 HP
Superpower, Pursuit, U-Turn, Bullet Punch

This is for revenge kills and keeping Gengar and Weavile under control. I also like having easy ways of disposing of things like Umbreon and Snorlax (without Fire Punch), and this is somewhat of a buffer against opposing Scizor without Brick Break of Superpower.

3. Gliscor, @Yache Berry
Impish; 252 HP, 252 Def, 6 Spd
Earthquake, Ice Fang, Stealth Rock, Roost

Sets up Stealth Rock, beats Metagross, CB Scizor, Breloom and Lucario. Also a good measure against Dragons once Celebi has paralyzed them, and can still take a hit and deal massive damage with Ice Fang if Celebi hasn't paralyzed them.

4. Tyranitar, @Leftovers
Careful; 252 HP, 216 SpDef, 40 Def
Payback, Curse, Sleep Talk, Rest

The basic idea behind this is "use Celebi or Gliscor to kill the Fightings and Grounds and Steels then set up." The EVs make it a great special wall, so any special attack other than Focus Blast or Aura Sphere will hardly leave a scratch (a max SpAtk Togekiss will barely 2HKO with Aura Sphere). It's also a counter to any kind of Latias, Cresselia, and pretty much any Calm Minder without a Fighting move (excluding Suicune). Absorbs status and stuff so other Pokes won't have to deal with it. Great way to deal with Azelf, too.

5. Latias, @Leftovers
Calm; 252 HP, 252 SpDef, 6 Def
Dragon Pulse, Toxic, Wish, Protect

The last one I have so far. Counters MixApe, most importantly, and kills or Toxic stalls the special sweepers whom Tyranitar cannot handle, most notably Togekiss and Specs Lucario. Also an answer to almost any wall without status recovery (or Toxic of its own), and provides Wish support to heal Scizor, and Tyranitar so that it doesn't need to commit to Rest.

Those are the five I have so far. I know I'd have a hell of a time dealing with Skarmory shuffling me around with Spikes and stuff, so the two sweepers I've considered most are Heatran and Magnezone. But like I said, they don't really "click" with the rest of the team. If you have any good ideas or helpful advice, don't hesistate to share. Thanks.

 

[Marble101]

As a side note: Pictures would help. you can copy and paste them straight form the strategy pokedex.
While you have covered a majority of poular sweepers, you have left out some pokemon that could give you some trouble:
1) Rotom-A. Known as one of the best will-o-wispers in the OU tier. It also functions as a bulky tank (or atleast mine does). It can burn Tyranitar and Scizor, while KOing Celebii, Latias and Either KOing Gliscor (Washing machine form) or do massive damage to it.
2) You also seem to have a problem with Lucario. Lucario can deal hefty damage to your team by means of Dual STABs and Priority moves.
3) On a similar boat as Rotom-A, Gengar can detroy your team if it has Focus Blast. Scizor and Tyranitar succumb to HP Fire and Focus Blast repectively. Then Latias and Celebii are easy pickings with Shadow ball. Only Gliscor stands a chance.
4) Your team can deal with many threats, but needs to be switching constantly to do so. Residual damage from Entry Hazards and Sandstorm are a huge risk for your team. As a result, you should pack a rapid spinner.

As for your 6th pokemon, I'd reccomend:
Starmie@ life orb
252 Sp. Atk / 252 Speed / 4 Def
Rapid Spin, Hydro pump, Ice BEam, Grass Knot / Thunder Bolt

This will allow your team to keep its offensive momentum while providing service as an antilead and rapid spinner.

Also, in my opinion, Azelf would also funtion in the last slot if you dislike Starmie.
As for the rest of your team, Tyranitar may be more of a burden than an asset simply because of Sandstream. In its place I would reccomend a Lucario or Infernape. Both would mix well. Lucario has access to priority moves but is at risk from Rotom-H. Infernape can funciton well as a cleaner, but sports no priority moves.

My final suggestion is to not use Latias. It makes 3/5 of your team weak to ice. Instead, use Vaporeon with a similar set but Surf instead of Dragon Pulse and tailor the EV's a bit differently.

 

[Starbuck]

Rotom can't do much to Tyranitar. It burns him, sure, but even Hydro Pump won't do much, so he'd be free to Curse and Rest as he pleases.
Gliscor has Yache so he can take a boosted Ice Punch. If I switch in on the Ice Punch, then I'd have some problems, so it'd take a bit of predicting. Even then, Celebi could survive an Ice Punch (not well, but survive it at least), paralyze it, then let Gliscor or Scizor have a go.
On Gengar, Scizor nearly OHKOs with Bullet Punch, and Tyranitar has the EVs to survive a Timid Life Orb Focus Blast. Disregarding all that, Sand Storm and Life Orb add up quickly.
What you said about entry hazards is true and I certainly considered Starmie. One thing about the Sand Storm is most of the people I battle use Tyranitar as well, and a Sand Storm is usually present, whether I cause it or not. Another thing, I just like Tyranitar. :p I've used the Curse set with great success before; it catches a lot of people off guard when their boosted special attacks don't do anything then they fall to Payback. Vaporeon's a decent option, but Ice moves really don't give me much trouble. STAB Ice Beam is a bit rare in OU, and most Ice Punchers fail to 2HKO Celebi, unless they're packing a Life Orb, in which case the residual damage wears them down. Still, you made a good point with Vaporeon. It won't take special hits nearly as well as Latias, but still fills the role and can take advantage of Gliscor and Tyranitar's water weakness.
Thanks for the advice.