So I'm going to be battling my friend irl. We both know all the mechanics of battling like IVs and natures and stuff, and we both have Pokemon trained in that respect. However, I haven't been in touch with the metagame for a couple of years, so I'm afraid my movesets may be a bit outdated.

I know for a fact that my friend has DDtar, Metagross, Scizor, Aerodactyl, Heracross, Dragonite Jolteon and Gardevoir among his choices. I suspect he's probably running a sandstorm team. Now here is my team, as it looks right now:

Jolteon @ Leftovers
Timid
6/252/252
Thunderbolt
Quick Attack
Substitute
Baton Pass

This was my staple lead back in 3rd gen, but I'm not sure how well it works now. I used to run it with a Salac Berry but Sandstorm puts a damper on that.

Bronzong @ Leftovers
Relaxed
(Forgot what EVs I used, but probably 252 HP and some in Def.)
Stealth Rock
Gyro Ball
Light Screen
Rest

This will be my main counter to Metagross, TTar, Scizor, and Aerodactyl (and to an extent Heracross). I'm not sure Light Screen fits on this moveset, I'm thinking of replacing it with EQ so it can hurt Metagross and Scizor.

Blissey @ Leftovers
Bold
252 HP / some in Def / some in SpA
Toxic
Ice Beam
Softboiled
Aromatherapy

I'm actually debating on whether or not to include her. Most of my friend's sweepers are physical, so not sure how well she'd help. I may replace Toxic with something due to the abundance of steel-types, and probably replace IB with Fire Blast.

Gengar @ Black Sludge
Modest
6/252/252 I reckon
Substitute
Hypnosis
Shadow Ball
Focus Blast

My special sweeper. The plan is to send it out on something that's not TTar, Scizor or Metagross, sub, hypno, then do as much damage as possible.

Gyarados @ Life Orb/Leftovers
Adamant
6/252/252
Dragon Dance
Waterfall
Earthquake
Ice Fang

Late sweeper, hopefully after I've taken out his Jolteon already. Need help deciding between Orb and Lefties.

Now, I need some help deciding a 6th party member. Choices for me are:
Metagross - Right now it runs an Agiligross set, but I can modify it for lead or CB.
Azelf - Nasty Plot variant (can change to Specs)
Porygon Z - also Nasty Plot
Ninjask - standard BPer
Starmie - Choice sweeper
Heracross - Scarf variant
Slaking - CBer

I also have a nice timid Heatran that I can EV train in a day or two. (We're playing with a level 50 cap, so no need to level it up)

Anyway, C&C are appreciated. Thanks in advance.