Arish Ashuvain Gauntlet is crafted with Blacksmithing in Mabinogi (gauntlets). 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 B and survives 30 uses; every crafting attempt spends one use.
Giant Alligator: field-boss kill reward from raiding it at Erkey Falls in Courcle.
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.
Sources that no longer exist: Eweca Orb (2013).
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
3× Iron Ingot — refine from Iron Ore (common low-rank Refining output)
3× Common Leather Strap — weaving at a spinning wheel (or common low-level monster drops)
Finishing (once per item)
1× Cheap Silk — Mobilizing the Expeditionary Force shadow mission reward