Stuck at the end, need some advice,especially griever

[PuPu]

youjirou i know everyone says dont level up to 100 etc etc but i cant resist taking on omega weapon and he always stays at 100 thats why i level up. do you think its best to do that or stay at 20/30 ?

No, Omega stays at your party's level. Given that he has such a massive amount of HP, it's recommended to fight him at as low of a level as possible.

I think that's only on the PC version. I'm guessing that you are using a the FFVIII Strategy Guide, which shows Omega's stats at lvls: 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100. This is probably because the maker of the guide probably used LVL Down to find out his stats, got them from the PC version, or used something like GameShark to alter his lvls, etc.

[Moon Rabbits]

Do what rubah said, level up with those abilities.

Also, what do you have junctioned? By that point in the game you should have high level magic, like Full-Life, Ultima, Holy, etc. At least I did. Junction appropriately and you should have 9999 HP on everyone, or close to it.

Also, spamming Aura+Limit Breaks+occasional Meltdown = win.

[~Cloud Strife~]

You should go to the under water research place at the most bottom left of the map and fight ultima weapon, you can draw ultima's from him which will increase your strength alot. You should draw 100 aura's from sefier and junction to hp to get 9999 hp.

I had zell, squall and rinoa in my party when fighting ultimecia and I was only hit twice because of invincible moon. Used aura + haste at the start of the battle then used had invincible moon used. Zells limit break (O+X then Right + Left) can get about 70 combo in 12 seconds if your quick enough at pressing them (on youtube some guy did a 138 or so combo against omega) and if you have something like 100 ultima's junctioned to zell's strength it should easily finish each stage of ultimecia and invincible moon, aura and haste should still be on. (I did not of squalls lionheart while fighting ultimecia x.x)

[snakebyte91]

youjirou i know everyone says dont level up to 100 etc etc but i cant resist taking on omega weapon and he always stays at 100 thats why i level up. do you think its best to do that or stay at 20/30 ?

No, Omega stays at your party's level. Given that he has such a massive amount of HP, it's recommended to fight him at as low of a level as possible.

oh well i like a challenge