Our next objective is to bring Mythril to the rebels, so we have go back to Altair, but we'll stop by Salamand to heal up and buy some magic.

Rest up and buy 3 "Life Tome" and give them to everyone, then exit the town. It's up to you if you want to buy other magic, but I don't find them useful.

• Walk to Poft
• Take the ship from Poft to Poloom
• Walk from Poloom to Altair

• Enter the rebel hideout
• Talk to HIlda, then select:
  • "Learn -> Dreadnought"
  • "Key Items -> Mythril"
• Leave the hideout
• Enter the weapon shop
• Talk to the old man inside, choose:
  • "Key Items -> Mythril"

Both weapon and armor shops have been upgraded, there are additional sellers who sell Mythril equipment. 

I do not recommend you buy any of them now, since you'll get a lot of Mythril equipment later in the game.