Here's the team I'm currently using in the Battle Tower. It's been working pretty well, but I need to know if it has any big weaknesses that are common in the BT. One thing I'm worried about is not having any never-missing attacks, considering that Double Team was very common in the Battle Frontier last generation.
GALLADE @ Expert Belt
Ability: Steadfast
(Adamant)
230HP/200ATK/52SPDEF/28SPD
-Psycho Cut
-Close Combat
-Leaf Blade
-Swords Dance
While his speed isn't the highest, he's bulky enough that he can usually take any hits he needs to. Most of his hits are OHKOs, but if I'm afraid it won't, I can just Swords Dance. Faster special sweepers usually can't KO him, but if he comes up against a faster physical sweeper, I can switch to...
TANGROWTH @ Leftovers
Ability: Leaf Guard
(Impish)
252HP/230DEF/28SPD
-Power Whip
-Knock Off
-Stun Spore
-Sleep Powder
He's such an awesome physical wall. Nothing can hit him hard, even if it's super-effective. He can even take some special hits thanks to his high HP. Basically, I bring him in if the other two can't take hits. He usually puts an opponent to sleep, or paralyzes if I just need a speed boost. Power Whip hits hard thanks to decent attack, STAB, and a high base power, and Knock Off eliminates threatening items like Leftovers or Life Orb.
PORYGON-Z @ Life Orb/Wise Glasses
Ability: Adaptability
(Timid)
6HP/252SPATK/252SPD
-Tri Attack
-Thunderbolt
-Ice Beam
-Nasty Plot
An excellent special sweeper, which is needed since the rest of my team is physical. Apparently, he's really fast because he's outsped both a Salamence and Garchomp (and they were downloaded from wifi with good movesets, so I'm assuming they had good speed EVs). Boltbeam covers almost everything that Tri Attack can't hit hard, and Nasty Plot is nice if I have a turn to kill (such as if Tangrowth put something to sleep).
GALLADE @ Expert Belt
Ability: Steadfast
(Adamant)
230HP/200ATK/52SPDEF/28SPD
-Psycho Cut
-Close Combat
-Leaf Blade
-Swords Dance
While his speed isn't the highest, he's bulky enough that he can usually take any hits he needs to. Most of his hits are OHKOs, but if I'm afraid it won't, I can just Swords Dance. Faster special sweepers usually can't KO him, but if he comes up against a faster physical sweeper, I can switch to...
TANGROWTH @ Leftovers
Ability: Leaf Guard
(Impish)
252HP/230DEF/28SPD
-Power Whip
-Knock Off
-Stun Spore
-Sleep Powder
He's such an awesome physical wall. Nothing can hit him hard, even if it's super-effective. He can even take some special hits thanks to his high HP. Basically, I bring him in if the other two can't take hits. He usually puts an opponent to sleep, or paralyzes if I just need a speed boost. Power Whip hits hard thanks to decent attack, STAB, and a high base power, and Knock Off eliminates threatening items like Leftovers or Life Orb.
PORYGON-Z @ Life Orb/Wise Glasses
Ability: Adaptability
(Timid)
6HP/252SPATK/252SPD
-Tri Attack
-Thunderbolt
-Ice Beam
-Nasty Plot
An excellent special sweeper, which is needed since the rest of my team is physical. Apparently, he's really fast because he's outsped both a Salamence and Garchomp (and they were downloaded from wifi with good movesets, so I'm assuming they had good speed EVs). Boltbeam covers almost everything that Tri Attack can't hit hard, and Nasty Plot is nice if I have a turn to kill (such as if Tangrowth put something to sleep).