HT Games
Instructions
Raft Encounter
Keep Banon alive. He's a unique character, so if he dies, your game is over. He also functions as the main healer of the party. His healing ability is unlimited, so don't worry about running down any magic points like normal healing spells.
Bring the Eyedrop item with you. Ultros has a blinding attack that will greatly reduce your ability to connect on your attacks. By using the Eyedrop item, it will remove the blinding effect.
Heal often. Ultros has a devastating blow called the "Tentacle" that will take off more than 200 hit points. Banon's healing ability comes in handy here, so make sure to heal your characters as soon as you get hit. Use a Phoenix Down if a character dies. Heal even if your characters have only small amount of hit points. Banon's ability is unlimited, so there's nothing to waste.
Keep on the offensive when you're not healing. Terra's Fire spell will do big damage, and Sabin's combos will wear Ultros down. The combination of Baron's healing and these offensive attacks will slowly defeat the octopus.
Opera House
Equip your characters with the best weapons. Get the Chainsaw for Edward in Zozo. This makes him one of your highest damage dealers. Equip the Fire Knuckle on Sabin, which you also get in Zozo. Ultros has a weakness to fire, so this does large damage.
Bring Green Cherry's or Remedy items to the battle. Ultros has an attack that will turn your character to an imp, greatly reducing both your attack and defense. If you leave them in that condition too long, you'll see your party die.
Keep on the offensive. Ultros presents less of a challenge here compared to the first bout, so as long as you keep doing Edgar's Chainsaw attack and using Sabin's combo attack, you can make quick work of the octopus.
Esper Mountain
Equip Strago with the Genji Glove, which allows him to carry two weapons. Equip two Fire Rods. Because Ultros is weak against fire attacks, your biggest advantage will be using these two rods to wither down Ultros.
Avoid casting the water-based spell Aqua Rake. Ultros is resistant to water spells, so casting it does nothing to him. Ultros has a high amount of hit points, so any round where you don't do damage hurts you over the course of the fight.
Sketch Ultros. Gradually Relm enters the battle. She has a special ability where she can sketch an enemy, taking their abilities. When you do this, it will automatically trigger the end of the battle.
Floating Continent
Cast fire spells on Ultros as much as possible. You should have the spell Fire 2 by now, so keep casting it. Hit him with Sabin's Fire Knuckle and whatever other fire spells you have in your arsenal.
Come prepared with ice spells. After you have done a certain amount of damage, Ultros summons another monster called Chupon. His weakness is ice, so use the spell Ice 2 spells to wear him down.
Focus on Ultros. Don't switch your attacks back and forth. Keep attacking Ultros until he flees the party. Switch your attention to Chupon only after Ultros is defeated. Keep casting ice spells until he, too, is finished.