Final Fantasy II/Mission to Salamand

Minwu the white mage
After you learn about the Mithril, you learn that you need to retrieve it somewhere from the northeast. Speak with Minwu to have him join your party and receive the Canoe required to cross rivers.

Minwu's equipment

As for any other character, don't upgrade Minwu's armor, unless you find some armor parts for free: this way his HP will be upgraded often. Instead, give him a shield (maybe Firion's), so that his agility and evasion can be upgraded. His starting weapon is a staff, so you can train him with that weapon type, that includes staves and maces.

Minwu's spells

Minwu starts equipped with most white spells, i.e. all except Slow and the three offensive ones.
 * Use massively Blink, because it helps upgrading evasion;
 * use as needed Cure, Life, Esuna, Basuna, Dispel and Fog;
 * use cautiously Swap, because Minwu could end up with low HP and no MP at all;
 * ignore Sap and Silence, as they're weaker versions of Fog;
 * use sparingly Protect, Shield, Barrier and Wall, because they work against the HP upgrades;
 * also use sparingly Teleport and Fear, because if enemies are defeated to quickly attributes won't be upgraded.

Minwu's attributes

He's a white mage, and as such has very high Spirit, Magic and MP. His other attributes are significantly lower than these three.

Towns of Paloom and Poft
If you have not done so already, make sure that at least one member of your party (e.g. Maria) can cast black magic: some monsters are highly resistant to physical attacks and are more easily damaged using magic. Blink is the most important white spell to buy in Paloom or Poft, because it works like a shield. Don't buy armor.

By talking to various characters, you can learn that the source of Mithril was to the north east. To re-establish it, you will need to reach Salamand, which is to the north-west of Poft. If you want to avoid walking, there are two shortcuts that can be used: a ferry from Paloom allows quick passage to Poft, and Cid has a charter Airship that allows travel to both Salamand and the Semite Cave.

Town of Salamand
After arriving in Salmando, you will find that the empire arrested most of the town and placed them within the Semite cave.

Don't buy the Exit/Teleport spell, because you can soon find it for free. Don't buy armor either.

Semite Cave
This cave is located to the southwest behind the mountain range, but can be reached directly using the airship.

Deep in the Semitt Cave there's a chest containing the Exit/Teleport spell. However, this is guarded by a turtle that is very resistant to physical attacks. If you do not have Ice spell and if Minwu was knocked out, you will have to exit the cave by walking.

BOSS: Sergeant
When you reach the bottom floor of the cave, head to the north and take the west door. The sergeant has a very high physical defense, so attack him with magic spells.

After the boss
Return to Altair and give the Mythril to Tobul. Now the two Weapons and Armor shops will be able to sell Mithril equipment. The only important thing to buy is a Mithril shield for Minwu, the rest is optional; as usual, don't buy armor parts.

Next, talk to Hilda to learn about the Warship.