Emerald & Ruby

[G SpOtZ]

I think you get HP Absorb from a house in Wutai. Final Attack is your prize for being REALLY good at the Battle Arena and spanking them big bad boss monsters.

you get MP Absorb from a house in wutai, actually.

For RUBY:

give cloud hades and either phoenix or life, preferably phoenix linked with final attack, but that i'm pretty sure that you have to get omnislash AND w-summon, and then go another round in the battle arena to beat proud clod to get final attack, so if you're too lazy for that, then don't. i don't think you need it anyway. as long as you have megalixers you should be good. Also equip cloud with kotr, and level it up as much as you can. 2 stars should be okay, but i recommend 3 just in case.
your other two characters should get some high level mimes, one of those characters should have an enemy skill with big guard.
you probably don't need to use ur ultimate weapons, so if there's any materia you feel like leveling up, you might as well throw in triple growth weapons. of course, if you've got nothing that you care to level up, just stick with ur ultimate weapons, or whichever strongest that you have. you can use ribbon accesories if you want, because the claws from the ground cause some status ailments. use whatever armor you think is best.

kill of two of ur characters before you enter the battle. that way, right when you enter, ruby can't quicksand anybody to kick them out of the battle. he'll put his claws right into the ground, making him vulnurable for attack. now what you need to do is cast hades first, then right after that revive ur characters because hades should buy you some time. have someone use a megalixer to fully cure everybody (because phoenix probably won't fully cure everybody) and then have another character cast big guard. then focus on destroying the lil claws from the ground. even though you have megalixers to keep you healthy, lack of materia is not a factor in this battle, so go ahead and equip someone with restore+all so you can cast regen, it's always useful. you can blast away with kotr and mimes, and if hades wears off, just cast it again (assuming it also has at least 3 stars) big guard also runs off quickly, so recast it and kotr mime again. it's a pattern, so it's not like it makes the battle fun, but it should definitely work. ruby will cast ultima every once in awhile, so use a megalixer. the only problem to this is that you have to waste a mime turn to use a megalixer, so you'll have to cast kotr again and again... hopefully you'll be able to keep it up.

[Light Mage]

You do get HP Absorb from Wutai as well.
(SPOILER)Go into the house at the bottom of the flight of stairs on the far right of Wutai - the Cat House, and climb up the stairs into a secret passage, you'll find HP Absorb in a chest there.

[Cruise Control]

I can't climb the steps, a cat is in the way.

[Shoden]

HP absorb you get in the crater.
Final attack from the Battle square's special fight.