I'm not sure if people still rate Battle Tower teams at all, or maybe everyone has moved onto the Battle Subway. But with my recent interest in Platinum's Battle Tower and a couple failed streaks, I figured I should try to get this team rated.
I can't remember the exact EVs I gave to Uxie, but the spread was intended to have it reach 136 speed after tricking the Scarf. The rest of the EVs were used to bring its special defense above its defense (so that Porygon and friends get an attack boost from Download), with the rest being poured into HP. As for the moveset, Trick should be obvious to give the opponent a Choice Scarf, while Thunder Wave negates the speed boost they get. Stealth Rock is there to break any Focus Sashes my opponent may have. And finally, when Uxie is done with everything else, Momento halves both the opponent's attack and special attack.
Careful, Clear Body
EVs: 252 HP / 100 Atk / 140 Def / 12 SpDef / 6 Spd
I believe this is pretty much the "standard" Battle Tower Registeel from what I'm aware of. The EVs were prety much taken from someone who managed to get over 2000 wins with a team that used Registeel. The set should be fairly straightforward. Sub helps to prevent hax, while Curse and Amnesia boost Registeel's stats. Iron Head gets STAB and has nothing immune to it.
EVs: 8 HP / 252 Atk / 248 Spd
The EVs may seem a bit awkward, but without at least 8 EVs in HP, my Salamence would have 168 HP at level 50, allowing it to only be able to make three subs. So, since I can increase speed with Dragon Dance, I decided to take 4 EVs from there and put them into HP, giving Salamene 169 HP and the ability to make four subs. As for the set, Substitute helps to protect against hax, as I mentioned with Registeel. Dragon Dance boosts both attack AND speed (something which Garchomp can't do), which allows me to outspeed the entire Tower after a few Dragon Dances. Finally, Outrage and Earthquake hit virtually every Pokémon except Skarmory and Levitating Bronzong for at least neutral damage.