Exarchic Coat of Casting ★★★★

Taken all the way down to base materials, one Exarchic Coat of Casting is 2 crafting steps deep and needs 4 intermediates — Grade 4 Intelligence Alkahest ×2, Solstice Ingot ×2, Thylacoleo Leather ×2 and 1 other — which resolve to 10 distinct raw materials totalling 37 units, plus 43 crystals.

That bill outweighs 11,564 of the 13,602 recipes tracked here and 1,713 of the 1,844 Leatherworker ones, and 4,464 recipes nest deeper.

Only 6 of those crystals go into the final step; the other 37 are burned by the intermediates, so the real crystal cost is 15 Wind Cluster, 9 Earth Cluster, 7 Wind Crystal and 3 other kinds.

The chain crosses three disciplines — Leatherworker to Lv 80, Alchemist to Lv 80 and Goldsmith to Lv 80 — so no single class can finish it unaided.

6 of the 10 raw materials come out of the ground, and 3 of them are time-gated: Hard Water (4:00, 16:00), Solstice Stone (2:00, 14:00) and 1 other. The widest gap between consecutive opening times is 8 Eorzean hours, about 23 real-world minutes.

Of the intermediates, Dwarven Mythril Nugget has the widest use: 154 recipes call for it, spanning seven of the eight crafting classes.