Perseus Tempestuous Lance is crafted with Blacksmithing in Mabinogi (weapon). This page lists everything needed to make it, checked against the game as it exists today. The interactive planner lives in the Blacksmith Companion.
How to get the manual
The manual is rank 3 and survives 30 uses; every crafting attempt spends one use.
Feth Fiada: Hard-difficulty reward from the Tech Duinn mission board. Unlock Tech Duinn during Generation 22, then board there with total level 3,000, up to 4 players.
Materials
Expect about 8 attempts per finished item (13% average progress per attempt). Per-attempt materials are consumed on every attempt; finishing materials once per item.
Each attempt uses
8× Vengeance-Imbued Alchemy Crystal — Hard Tech Duinn missions drop
8× Vengeance-Imbued Blade — Hard Tech Duinn missions drop
8× Vengeance-Imbued Old Tree Fragment — Hard Tech Duinn missions drop
2× Finest Firewood — Carpentry production (refined from Firewood)
2× Large Nail — hit props (lamp posts, signs, statues) or common low-level monster drops
Finishing (once per item)
15× Functional Geata Fragment — Feth Fiada raid drop
3× Misty Red Gem — Tech Duinn hard difficulty mission drop
3× Bloodstone — gather via Metallurgy at gem sites, or Veteran Dungeon/Paradise of Gems drop