Zidane will find himself in the expanses of space. When you are back in control of him, move forward until he reaches the end and a short cutscene involving more dialogue with Garland will continue.
The creatures that you fight in this area look very similar to the bosses that you just fought, however they have less HP and are vulnerable to a number of additional status effects. Make sure to make use of 
Silence and stick to spells to attack a Behemoth if you run into one (or just use Zidane’s Flee ability).
Follow the pathway along until for a few screens until you reach another Save Point orb. Save your game, use a 
Tent and now you have the option of Teleporting back to earlier areas of Memoria.
You cannot warp back to this point though and will have to travel back through Memoria and the Crystal World on foot.
It’s time to prepare for one last boss fight. The boss uses some Wind-based elemental magic attacks so equip 
Ribbon to each of your characters if possible to absorb those attacks. Make sure to have Zidane in the party so that you can Steal every available item.
Move forward into the next room when you are ready.
Level: 74
HP: 55,535
Deathguise has a number of attacks which include:
Deathguise has two forms - open and closed. It will always start the battle by casting Meteor, but from there its attacks will change depending on whether it is open or closed. When its wings are open it will use its physical attacks. It will focus on magical attacks when its wings are closed.
There isn’t much strategy to this fight - just keep your party member’s HP high in anticipation of Meteor casts which can do a ton of damage.
Steal:
Elixir (common)
Black Belt (uncommon)
Duel Claws (very rare)
Drops:
Wing Edge (common)
Phoenix Down (uncommon)
Ether (rare)
Elixir (very rare)
A video of the battle is included below:
You have now reached the end of the game and are at the final battle stage. Do not approach Kuja just yet! Go back and save your game at the Save Point while you have an opportunity.
You can take this last chance to go back and make any final preparations that you’d like and complete any of the side quests that you may have missed. Check out the Final Preparations page for more information on some of the side quests that you can complete.
Note: You are already strong enough to defeat Kuja if you have made it this far and you do not need to complete any of the items on the “Final Preparations” page. The Final Preparations page contains end-game content for those that want to master the game. Kuja is not the most difficult battle in the game and is simply the last chapter of the Final Fantasy IX story.
Clicking the “Next Page” button below will take you to the Final Preparations page, but you can click the link below if you would prefer to go directly to the battle against Kuja:
