Burning Mansion (Thamasa)

You'll find yourself in the Burning Mansion in Thamasa. Your immediate goal is to confront the boss, the Flame Eater, and then locate Relm.

The Flame Eater has a variety of attacks, including basic attacks, Fire spells (Fire, Fira, Firaga), Fireball, Reflect, Protect, and a new attack called Bomblet. This Bomblet attack hints at the appearance of enemies like Balloons and Grenades, which you might have encountered before.

For this fight, your best bet is to have Strago continuously use his Aqua Breath ability. It's highly effective against this boss.

Simultaneously, have another party member summon Kirin. If you have Shiva available, summon her as well, along with another Esper that isn't Ifrit.

If Terra is in your party and has entered her Trance state, let her attack. Her power will be significantly boosted. Similarly, Locke can primarily focus on the Attack command.

If you've equipped Terra with Blizzara and she enters her Trance, her attacks will deal around 5000 HP damage. Two such powerful attacks should be enough to defeat the Flame Eater.

Remember that Aqua Breath is also very useful if any Balloons appear during the battle.

Once the Flame Eater is defeated, make your way to the back of the mansion. You'll find Relm there. You'll both be caught in a near-miss with falling flaming rubble, but you'll manage to escape.