I'm sorry I couldn't give you this before but now I can answer your question about the Tartarian.
A good way to deplete his HP is to get the Dark Matter (bought at the Treno auction) and use it on him. Then just keep your characters in good health (try to attack, too) and wait for someone to get trance.
Use it on him when he is OPEN. This causes regular damage(he dosen't open only once, but many times). Keep doing this until he is dead. I think you get battle boots and I know you get good EXP and AP. Good luck!
I know that there are some really confusing cheats about Ozma on here, so I will make it clearer.
Ozma is an optional boss. He is the most powerful boss in the game, so you need to be well prepared.
Equip your people with the best shadow-absorbing/shadow-resistant armor you can get. Epuip as many abilities you can. Get as many battle attacks as you can learn.
I would suggest the party of Zidane, Garnet(Dagger), Vivi, and Steiner. Try to get counter magic for Vivi, it really helps. Be at least at level 75. When you are ready, save, get a gold chocobo (the flying kind) and go to Chocobo's Air Garden.
Here you will see the two islands. Go to the second one and go to the big brown rock-like looking thing that looks like it shouldn't be there and examine it.
Mene will say he has a bad feeling and senses a powerful monster in the eidolon cave (the rock).
You can ready your characters, quit,etc. Hit to continue option and you will go to battle with a big rainbow colored ball called Ozma.
Immediently attack with all you got. Try use Flare for Vivi, shock for steiner, attack regularly for Zidane, and have Dagger summon Bahamut. By this time Ozma will have attacked with something. If Dagger needs to heal people, let her heal. Keep your HP up!
This is a long battle (about 45 minutes at least). If you happen to have the Dark Matter, use it! Do any attacks that will cause a lot of damage.
Ozma uses a variety of attacks (magic only). These attacks include Curse, Flare, Doomsday, Holy (He might use only Level 7),Curaga, and Meteor.
After beating him you get extreamly good EXP and AP. You also get a Dark Matter, a Pumice (accesory needed to learn Ark), and the Ozma card.
He is really easy(to me) He attacks with his sword and uses curse. Use Holy on him a lot and he will die easy. You can get the Save the Queen, a pumice, ethers, Tin Armor, etc.
I also have a question: What do you REALLY do with the Save The Queen? Also, where are all the Stazzello located?
Added by: Final Fantasy Ti.. , ID#2441