You need to have 3 lines of description per team member, it's in the rules.
Buuuuuut here goes nothing anyway.
Talonflame should not be holding a King's Rock, it is a crappy item based on hax. It looks like revenge killer Talon, so I would recommend Choice Band or Sharp Beak if you don't like being locked into a move. Flare Blitz is much better than Flame Charge, as Talon needs the power and it doesn't need the speed. Acrobatics is crappy because you have an item. It is 55 BP and will become 110 if your item is knocked off, which is still less powerful than Brave Bird. U-Turn is a very good replacement that will allow you to scout and break Sturdy, sashes, and Multiscale. Me First can work, but it is very inconsistent. I recommend Sleep Talk or Tailwind if you go for Choice Band, and Roost if you go for Sharp Beak. Also, it is very important to shift 4 EVs from HP -> Defense, as that will allow you to switch into rocks twice and not die.
Venusaur is not viable in OU outside of Chlorophyll sweeper. Mega Venusaur is one of the best defensive pokemon in OU.
Venusaur (F) @ Venusaurite
Ability: Chlorophyll
EVs: 252 HP / 240 Def / 16 Spe
Bold Nature
IVs: 0 Atk
- Giga Drain
- Sludge Bomb
- Synthesis
- Leech Seed / Hidden Power Fire
You should definitely use this, as you currently don't have a mega.
Slowbro looks good, but you should definitely replace Yawn with Slack Off so you can recover more HP and counter the threats you need to.
Tyrantrum... I have no idea. He is rather slow, and his rock typing is bad, so I will assume he is outclassed as a Dragon Dancer in OU. The best (non-mega) DDers in OU are Dragonite and Gyarados, and Garchomp is very good with Swords Dance
Latios looks very good, but I have no idea what is going on with HP Steel. You have many better options: HP Fire for Ferro/Scizor, HP Fighting for Ferro/TTar/Heatran, EQ for Heatran, T-bolt for Azu/Gyara, Surf for Heatran/TTar, and Memento for the free switch.
Pachirisu is not good outside of doubles. Volt Absorb and Follow Me creates its niche. Super Fang and Nuzzle are cool, but you are slow and even with the defensive investment, you are destroyed by OU's top threats. This thing will have a very hard time switching in. If you still want an electric type, Thundurus-I is awesome for his speed, power, and Prankster. You can also go mixed with Superpower and Knock Off.
You also need something to set up rocks for you, as they are great for every team. Maybe replace Tyrantrum with a rocks user.