Void Robe (M) is crafted with Tailoring in Mabinogi (robe). This page lists everything needed to make it, checked against the game as it exists today. The interactive planner lives in the Tailoring Companion.
How to get the sewing pattern
The sewing pattern is rank 1 and survives 30 uses; every crafting attempt spends one use.
Rundal Advanced / Advanced Hardmode / Peaca Intermediate| Dead-End Chest Reward: Run Rundal Advanced Hardmode and open the hallway dead-end chests for a chance at Destructive gear sewing patterns.. Enter through the Rundal Hardmode Dungeon altar; Peaca Intermediate's own dead-end chests do not carry these patterns.
Materials
Expect about 10 attempts per finished item (10% average progress per attempt). Per-attempt materials are consumed on every attempt; finishing materials once per item.
Each attempt uses
4× Finest Silk — weaving on a loom, higher rank
3× Finest Fabric — weaving on a loom, higher rank
4× Tough Thread — weaving Thin Thread Balls
7× Broken Magic Essence — Drops in Alby, Ciar, or Rundal Advanced Hardmode dungeons.
4× Condensed Chaotic Rune — Alby/Ciar/Rundal Advanced Hardmode dungeon drop
Finishing (once per item)
5× Finest Finishing Thread — Buy directly from any general goods NPC shop.