Omega

I recommend bringing plenty of thunder books and more importantly, plenty of X-Potions or Elixirs.  To help even more, you should bring a lot of Ramuh Summon Stones or Upper Level Stones such as Bahamut or Odin Stones.  And also, the Random Summon Feather helps - if that summon dies, you don't lose the feather.

Level 70 is a good start for Chocobo.  And you should have a very strong saddle.  If you plan to claw Omega to death, bring really good claws like Genji's+50.  This fight will take time, and other Komega enemies will interfere.  Take them out and continue with Omega.

Killing Omega is reason enough to go after him.  But the real reason for tackling Omega isn't for the exp or for the glory.  It's for getting the Omega Essence.  This essence when blended with a claw or saddle on the stove creates the Titan Claw or Titan Saddle.  Each have a +40 base value and a max level of 99.  To get the essence, bring lots of empty bottles (40 or so is sufficient.)  Also bring lots of identify cards to see how close to zero Omega's HP is.  You should bring it down within 100 HP at least.  If you've been watching the damage you deal, you might be able to bring it down lower than this.  Also, stones or power stones help bring the HP from 100 down to less than 20.  Each bottle does 4 damage.

After you have the essence, if getting the essence was a nightmare and a half, consider waiting to get a divide card and using it on the essence to get another one just like that.  You should only want two - one for the Titan Claw and another for the Titan Saddle.

Another very minimal reason for defeating Omega is for the very miniscule chance that Omega will drop the Pink Tag.  This item turns all the white text in the game to pink.  (It's sort of dumb, but it's a unique artifact.)

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