Still in Narshe, still with Mog in your party? No? Fix that.
At the town entrance, go north into the mines. There, go along the first eastbound path and along it to the outside again. Go along the bridge to the west, then go up the stairs to the north into the cave. Continue outside the cave and go up the mountain path. Also consider learning Mog’s final Dance up here. If that blue enemy gets too close…
The Ice Dragon has the expected move repertoire, also a rather short one: a basic attack, Hit (twice as powerful), Absolute Zero, Avalanche , and Northern Cross . There is a VERY, VERY cheap strategy to end this very quickly, sort of. Inflict Berserk on the Ice Dragon – a spell you should’ve had a long time ago – then summon the Phantom Esper to obtain invulnerability. Then just attack, attack, attack, attack, and loop from the first word on this line. Another way - use Confuse on it and sit back.
Yet another - hit it with Darkness, Silence, Haste, and Poison. This will effectively make all but the rarest of Attacks/Hits hit, in which case a Hi-Potion may be in order. The Haste increases that risk, but also ups the speed at which the Ice Dragon dies.
Whether you fight or not, go north and use the Save Point to heal up and … well, not Load! Continue north and approach the frozen Esper from way-back-when. This time, though, Terra won’t go crazy; rather, the Esper within goes crazy and attacks you.
Valigarmanda can use a basic attack, Hit, Blizzaga, Freezing Dust , and Rasp – all fairly basic attacks.There is not a lot to say here. Begin by using Zona Seeker to raise your Magic Defense (like it needs it all too much), and Kirin for some Regen. Go to having Ifrit summoned for some Fire-elemental damage, and then proceed to cast Fire/Fira/Firaga, depending on what you have. In the case of Sabin, the Rising Phoenix Blitz is preferred unless he DOES have a decent-powered Fira/Firaga.
After the battle, there will be a bit of conversing before Valigarmanda turns himself into a Magicite for your own perusal. PUT. HIM. ON. SOMEONE. He teaches "-ga" spells and has a decent summoning attack. Then hop into the cliff opening nearby.
Local Enemy Bestiary
When you land, you’ll be able to go to three portions of the cave. Take the middle one to find a chest with an X-Ether in the upper chest. Return to the cavern entrance and go into the western cave. Look out for the dark tiles around there, for they are pitfalls. You don’t wanna fall. If you do, you can easily get back to where you were through the northern doorway.Open the chest here to find three Tonberries. Personally, I’d avoid them, but do what you want.
From the chest, go back to the cavern entrance. Now, go through the northeastern door to where you found the X-Ether. From the chest, go northeast and downstairs. Use the small staircase to reach the higher ledge, then go along the path southwest to find a Gauntlet in a chest on the way. Go east, north, and upstairs. In this area, go along the path eastward, triggering the second switch you find. In this new area, go north and heal up. Examine the bone statue to find some Midgardsormr magicite, then fight the Yeti.
The Yeti – a.k.a. the Himalayan Abominable Snowman – can use a basic attack, Tackle (triple-power attack), Jump, Hailstone , Snowstorm , Snowball , and Avalanche . At one point, he’ll use a Green Cherry to put Haste, Protect, and Shell on itself.
Cheap strategy time! Like with the Ice Dragon, inflicting Berserk on the Yeti, summoning the Phantom, and attack works just fine. Otherwise… Meh. Use Fire-based stuff (Fire, Fira, Firaga, Ifrit, the usual) to deal some heavy damage. Use Dispel once the Yeti uses its Green Cherry, and just be sure to have someone healing when needed.
After the fight, speak with Umaro with Mog in your party. Mog "entices" Umaro to join your group, with that Yeti (who is Umaro, obviously) rushing off to the Falcon.