I'm in the Battle Tower on Pokémon Platinum. After losing my streak a couple of times. I finally reached Palmer on the 21st streak.

However, he almost swept my team. I don't really know on how else i'm supposed to beat him.

My team can definitely kill him but he's a bit stronger than me.

This is the team I'm using for Singles.

~Lucario

Nature: Jolly

Ability: Inner Focus

Item: Expert Belt

Moves:

ExtremeSpeed

Aura Sphere

ThunderPunch

Bone Rush

~Espeon

Nature: Adamant

Ability: Synchronize

Item: Mind Plate

Moves:

Psychic

Psybeam

Quick Attack

Toxic

~Empoleon

Nature: Impish

Ability: Torrent

Item: Lum Berry

Moves:

Aqua Jet

Shadow Claw

Surf

Grass Knot

I'm planning to replace Psybeam/Toxic with something else but I'm unsure what.

I also have these two Pokémon who I used for the Pokémon League if it helps, however they didn't do that well, which is why I'm using the three Pokémon above.

~Altaria

Nature: Modest

Ability: Natural Cure

Item: NeverMeltIce

Moves:

Ice Beam

Fly

Roost

Dragon Pulse

~Roserade

Nature: Hasty

Ability: Poison Point

Item: None

Moves:

Stun Store

Giga Drain

Leech Seed

Petal Dance

Any tips and team/moveset suggestions for Palmer? Thank you guys in advance.