Shinryu's Ephemeral Katana ★★

Taken all the way down to base materials, one Shinryu's Ephemeral Katana is 3 crafting steps deep and needs 3 intermediates — Chromite Ingot ×3, Torreya Lumber ×2 and Molybdenum Ingot ×5 — which resolve to 8 distinct raw materials totalling 61 units, plus 49 crystals.

That bill outweighs 13,148 of the 13,602 recipes tracked here and 1,815 of the 1,932 Blacksmith ones, and 337 recipes nest deeper.

Only 4 of those crystals go into the final step; the other 45 are burned by the intermediates, so the real crystal cost is 25 Fire Crystal, 8 Earth Cluster, 8 Fire Cluster and 2 other kinds.

The chain crosses two disciplines — Blacksmith to Lv 70 and Carpenter to Lv 70 — so no single class can finish it unaided.

4 of the 8 raw materials come out of the ground, and 2 of them are time-gated: Chromite Ore (10:00, 22:00) and Torreya Log (6:00, 18:00). The widest gap between consecutive opening times is 8 Eorzean hours, about 23 real-world minutes.

Of the intermediates, Chromite Ingot has the widest use: 121 recipes call for it, spanning six of the eight crafting classes.