I'm not very experienced in competitive battling or things of that sort, but here is my team created for the purpose of beating the single battles of the Battle Tower (which it did in a few tries.) I might (just might) try making them a 3 man competitive team.
Suggestions are ofcourse welcome.
Salamence (Adamant) @Focus Sash
EVs: 252 Att, 252 Spd, 4 HP
Salamence (nicknamed Pestilence) is my lead. I find that it was a very decent scout with a choice variety of attacks to take out potentially dangerous Ice and Dragon types. When confronted by a Pokemon that isn't too much a threat Salamence proceeds to power up with DD. The Focus Sash ensures that it stays in battle to deal a considerable amount of damage.
Electivire (Adamant) @Salac Berry
EVs: 252 Spd, 200 Att, 56 HP
Electivire serves the role of physical damage. A range of typed moves to beat down whatever may have managed to defeat Salamence, a bit on the sluggish side compared to his teammates so was given a Salac Berry so he may be able to beat faster opponents.
Latios (Timid) @Leftovers
EVs: 252 Spd, 200 Sp. Att, 56 HP
-Surf (considering replacing.. can't remember why I had it there)
Latios (nicknamed Boost) serves the role of special sweeper and a switch for Pokemon who are bound to try to Earthquake Electivire. Built to outspeed almost anything in the BT and with a decent range of it covers what Electivire couldn't handle.
Not much powering up and special setting up going on in this team, the range of attack on them seem to be enough to just go all out offense, what do you guys think?