Emerald Fuse is crafted with Hillwen Engineering in Mabinogi. This page lists everything needed to make it, checked against the game as it exists today. The interactive planner lives in the Hillwen Companion.
Recipe availability
Emerald Fuse is a rank C Hillwen Engineering recipe with a best success rate of 98% at rank 1 and dan ranks.
Materials
Each craft uses
1× Emerald Core — the bottleneck. Tanky Emerald mob drops, Hector's daily (1/day), Seal Merchant Mondays 1 for 2 seals (10×/week)