Similarly to Vanilla’s Inventory, Papi’s Stock gets reset when you start a New Game+. However, you don’t need to go through the process of recruiting her again, unlike the Vampire Girl.
The only prerequisite of this quest is Papi being a Companion. She needs to be in the party when you speak with the Blacksmiths.
- Get the Gold Ore from Midas Abandoned Mine.
- Talk to the Midas Village Blacksmith, he’ll agree to teach your Dragon in exchange for a Stone of Chaos.
- Go get the Stone of Chaos (they’re dropped by monsters from the first Tartarus).
- Talk to the Gold Smith again and give him the Stone (unlocks Golden equipment, gives Papi the blacksmith Achievement)
- Advance the main quest to the point where you fight Page 65537.
- After defeating her go talk to the Pope.
- Go to the Amos Mountains and get the Mithril Ore.
- Talk to the San Ilia Blacksmith, who’ll say that you need strong faith to forge Mithril.
- Recruit Sofia, Christie or Rosary (Sister Lamia, Succubus Nun and Slug Nun respectively).
- Get one of them to 10 affection and talk to them in the Pocket Castle to get the Proof of Faith.
- Talk to the Mithril Smith again and show him your Proof (unlocks Mithril equipment).
- Go pay a visit to the Lizard Boss in the Saloon Mine, after defeating her you can take the Crystal behind her throne.
- Go to Saloon and take a look at the Blacksmith’s wares.
- Talk to her again and she’ll agree to teach Papi in exchange for Star Sand.
- Go get it from one of the chests at Saloon Hill.
- Deliver the Sand to the Crystal Smith (unlocks Crystal equipment, gives First class blacksmith Achievement).
- Advance the main quest until you prove yourself in the Coliseum for Grand Noah Queen.
- Get the Dragon Bone Ore from the cave south of Grand Noah.
- Give it to the Grand Noah Blacksmith.
- Get the Fighter's Badge from the Coliseum.
- Show it to Grand Noah Blacksmith (unlocks Dragon Bone equipment).
- Get the Orichalcum Ore from the cave west of Gold Port.
- Give it to the Dragon Girl in Gold Port Smith.
- Get the Dragon Forge Hammer from the Northern Undersea Temple.
- Show it to the Dragon Blacksmith in Gold Port (unlocks Orichalcum equipment).
- Get the Rainbow Ore from The World Tree.
- Talk to the Elf blacksmith on Fairy's Island (unlocks Rainbow equipment) after resolving the Queen Elf situation. (Not sure if any pre-reqs are needed for this scene, it just automatically completed for me).