Warrior Axe 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 4 and survives 30 uses; every crafting attempt spends one use.
Taunes: blacksmith NPC in Vales. Sells weapon blueprints at his shop (54,000 gold).
Red Dragon: field raid boss in Zardine's volcanic plains. No requirements; fight it north of Raspa Volcano in Zardine during twice-daily spawn windows.
Yeti: field boss roaming Physis's open areas. Drops the Broad Axe manual.
Giant Lion: field boss in Courcle's meadows, spawns twice daily.
Materials
Expect about 3 attempts per finished item (35% average progress per attempt). Per-attempt materials are consumed on every attempt; finishing materials once per item.
Each attempt uses
6× Iron Ingot — refine from Iron Ore (common low-rank Refining output)
3× Copper Ingot — refine from copper ore
3× Silver Ingot — refine from silver ore. Mine it in Barri Dungeon or north of Tory Ravine