Natures would be nice, even if you can't change them, so we can recommend appropriate sets.
Charizard @ Life Orb / Choice Specs / Expert Belt
~ Flamethrower
~ Focus Blast
~ Air Slash / Overheat
~ Dragon Pulse / Overheat
Special attacking Charizard. Overheat grants you an incredibly powerful hit-and-run move if you really need it.
Charizard @ Life Orb / Expert Belt
~ Swords Dance
~ Flare Blitz / Fire Punch
~ Earthquake
~ Dragon Claw / Rock Slide
Physical attacking Charizard. If you have Platinum then Fire Punch may be preferable to Flare Blitz so that you don't lose HP. On a side note, moves such as Blast Burn that force you to do nothing on the turn after you use them are generally not worth it. They may seem cool, but that one turn is enough for a smart opponent (assuming you use this team against other people) do have a free switch, attack, or stat-up/status move.
Venusaur @ Leftovers / Black Sludge
~ Sleep Powder
~ Leech Seed
~ Energy Ball / Grass Knot
~ Sludge Bomb
Put stuff to sleep then sap their health with Leech Seed. Sludge Bomb hits Grass-types that are immune to Leech Seed.
Tyranitar @ Leftovers
~ Rock Polish / Swords Dance
~ Stone Edge
~ Earthquake
~ Crunch
Ingame Tyranitar likes Dragon Dance normally, but Rock Polish works too. Swords Dance if you don't care about Speed and would rather annihilate slower opponents.
Articuno @ Leftovers
~ Ice Beam
~ Roost
~ Toxic
~ Substitute / Reflect / Water Pulse
Articuno's movepool is pitifully small. Roost keeps you alive and removes that hideous 4x Rock weakness for a turn. Toxic wears down opponents. Substitute keeps you alive even longer, Reflect helps the team, and Water Pulse is a lol move that can actually damage Fire-types.
Kingdra @ Leftovers / Lum Berry / Life Orb
~ Dragon Dance
~ Outrage
~ Waterfall
~ Substitute
Platinum Kingdra that doesn't need Rain to be effective. Since you have Tyranitar, this is the one to use, since it isn't messed up by Sandstorm. I suppose a special set is okay to use, but special Kingdra needs Rain, and that isn't happening easily if you have Tyranitar in the way.
Scizor @ Leftovers / Life Orb
~ Swords Dance
~ Bullet Punch
~ Brick Break / Superpower
~ X-scissor / Night Slash / Roost
Platinum Scizor, pretty standard fare right now. If you don't have Platinum then Iron Head is an acceptable alternative to Bullet Punch, but really, Bullet Punch is what makes Scizor shine.
This team should do fine ingame. But if you want to use it competitively, you are in for rough times. You have no Pokemon to use Rapid Spin and get rid of Stealth Rocks that will ruin Charizard and Articuno. And frankly, without natures or proper EVs, you will likely lose. But again, if you use this ingame then you should be fine.
