Halp - Battle tower.

[joeypants89]

I'm relatively new to Battle Tower etc.; it never really appealed to me on previous Pokémon games so I ignored it.
I'd like to request a little help now that I've started taking the BT more seriously.

Here's my team:

Glaceon @ Wise Glasses
Lv. 96 (Modest)
252 SATK. 252HP, 6SPD

- Ice beam
- Wish
- Substitute
- Yawn

Spiritomb @ Wise Glasses
Lv. 96 (Modest)
252 SATK, 252 HP, 6 SPD

- Shadow Ball
- Hypnosis
- Dream Eater
- Calm mind

Metagross @ Life Orb
Lv. 98 (Adamant)
148 HP, 252 ATK, 110 SPD

- Meteor Mash
- Iron Defense
- Earthquake
- Thunderpunch

Gorebyss @ Leftovers
Lv. 100 (Impish)

- Surf
- Amnesia
- Agility
- Baton Pass

Garchomp @ Life Orb
Lv. 100 (Adamant)

- Swords dance
- Earthquake
- Stone Edge
- Fire Fang


Any comments / advice would be extremely welcome. I have no qualms with re-EV training my team or substituting Pokémon for others; I enjoy leveling. :P
I'm not very familiar with terms etc. but I'm sure I need some sort of wall?

Thanks in advance. :)