Location: Kandorean Temple
HP: 150 each
Strategy: Before this battle you should equip the Mysterious Card to Sheba, because they are resistant to wind attacks. Use Jenna's Flare Psynergy, Sheba's Juggle, and Felix's normal attacks. If you get to hurt use Felix's Cure or an Herb.
Location: Yampi Desert
HP: 1060
Strategy: Start the battle by unleashing Djinn. After you have enough on standby, use your strongest summons. Use Jenna's Psynergy if the summons don't finish it off. Use Herbs and/or Felix's Cure if you get hurt.
*SPOILERS*
Location:Eastern Alhafra
HP: 1000(Briggs) 200(Per Sea Fighter)
Strategy: This Battle will be very hard if you haven't completed Air's Rock. Kill Briggs first because he calls in more Sea Fighters. All Psynergy Works Well. Use summons for an easier win. Be careful, because the Sea Fighters may use Oil Drops and Echo Cut which can cause serious damage, so keep an eye on your health.
Location: Lemurian Ship
HP: 2300
Strategy: Before the battle put four Mars Djinn on standby. Start off the battle by summoning Meteor with Jenna. After that, keep using Djinn (Mars work best) to hurt it and heal yourself when your HP drops below half.
*SPOILERS*
Location: Gaia Rock
HP: 3500
Strategy: You should complete Aqua Rock before attempting this battle. Put all your Djinn on standby except four of Jenna's. Summon all the level four summons(Judgement, Boreas,and Thor). After that, keep unleashing Djinn and using summons. Jupitor works best. Make sure Jenna has four Djinn so she could use Healing Aura.
Location: Champa
HP: 3800
Strategy: Go into the battle with four Mercury Djinn on standbye, but not Shade. Start off by summoning Boreas, and using strong Psynergy like Ragnarok. Have Sheba use spells like Impact, to raise stats. Make sure Jenna uses Healing Aura, and Piers should keep unleashing/setting Shade.
Location: Sea of Time
HP: 5000
Strategy: Before going into the battle, equip the Trident on Felix, and have four Mars Djinn on standby. Have Felix use the Trident, Peirs unleash Shade, and Sheba summon Meteor. Have Jenna heal throughout the battle. After you summon Meteor Poseidon should almost be dead. Just keep using the Trident and unleashing Djinn.
Location: Trial Road
HP: 3000(Moapa), 2000(Per Kinght)
Strategy: You should try to finish Trial Road first, and don't put weapons in the chests, put armor, rings, etc. Focus first on Moapa. Have Felix use his strongest psynergy, Jenna Heal, Sheba cast status-raising spells such as High Impact, and Piers should keep unleashing/setting Shade. You'll need to keep an eye on your health, as the Knights sometimes use Bramble Seeds, which can cause considerable damage.
Location: Jupiter Lighthouse
HP: 4250(Agatio), 3200(Karst)
Strategy: At first, you only have Felix and Piers in your party. Another party member will come every two turns. Therefore, before they come, have Felix attack and Piers heal. Focus first on Karst. Once the other two arrive, Have Jenna heal throughout the battle, and have the others eith use strong Psynergy moves and/or deploy/summon Djinn. Once you get Karst down, Agatio shouldn't be too hard, as Karst was the one with the healing powers.
Location: Mars Lighthouse
HP:5700(Big One), 5350(Small One)
Strategy: Before the battle, make sure to have the Sol Blade equipped to Felix. Focus first on the smaller one (it heals). Have Shebs use spells such as High Impact, and have Piers use his strongest Psynergy/Djinn unleashes, as they are weak against water. Once the small one is gone, the big one should not be too hard. *FYI: The big dragon has Agatio's powers, and the small one has Karst's.
Location: Mars Lighthouse
HP: 5000(First Head), 4200(Second Head), 3700(Third Head)
Strategy: Being a final Boss, the Doom Dragon will certainly not be an easy battle. It might be a good idea top complete the Sidequests first. Whether you do or not, though, you should be at level 45, at least. Make sure the Sol Blade is equipped ot the person with the most attack points. Before going into this battle, make sure to have 8 Venus, 8 Jupiter, 8 Mercury, and 9 Mars Djinn on standby. For your first move, have Piers and Sheba both summon Eclipse, Jenna summon Iris, and Felix summon Charon. (*Note: Charon and Iris are only available if you have transfered data with all 28 Djinn from the first game.) Once you kill the first head, it will use Cruel Ruin about 8 out of 9 turns. After it uses Djinn Strom, switch parties so that the first four can recover their Djinn. If you need to revive a party member, use Revive or a Water of Life, but not a Djinn. Try to use Wind Psynergy and Wind Djinn, as they are the Dragon's weakness. However, try not to use Earth moves any more than you have to, because the dragon is resistant to them.