The Best Combination:

The best materia combination goes like this:

1. Firstly Equip 'Mega All'

2. Mix:

'Quadra Magic' with 'Comet 2' (this will get you 4 Comet 2's)
(4 x (7 x 9999) damage)

3:Then Mix

'W-Magic' with 'MP Boost' (i forget the actuall name, it's the one that gives you extra damage but uses more MP)
(8 x (7 x 9999) damage)

4:Then Mix and then Cast

'Reflect' with 'MP Absorb' (on all your own characters obviously because of 'mega all')

5: Then cast 'Comet 2' with 'W-Magic' on all you own characters. This means you will get 2 (from W Magic) x 4(from quadra Magic) thats 8 allready. Then 3x all that from casting it on the three characters of your own because it will relfect of each of them in turn. Which means you get 24 'Comet 2' spells in 1 turn! That's 24 x 7 = 168 x 9999 dame in 1 turn

THATS 1680000 DAMAGE!!!!!!!!!!!!!!!

YOU CAN KILL RUBY OR EMERALD IN 6 or 7 turns... OMG!!!

Good Luck