Dwarven Mythril Manatrigger

Taken all the way down to base materials, one Dwarven Mythril Manatrigger is 2 crafting steps deep and needs 4 intermediates — Dwarven Mythril Ingot ×2, Stonegold Ingot ×2, Dwarven Mythril Nugget ×1 and 1 other — which resolve to 7 distinct raw materials totalling 29 units, plus 54 crystals.

That bill outweighs 10,170 of the 13,602 recipes tracked here and 1,176 of the 1,932 Blacksmith ones, and 4,464 recipes nest deeper.

Only 14 of those crystals go into the final step; the other 40 are burned by the intermediates, so the real crystal cost is 26 Wind Crystal, 21 Fire Crystal and 7 Earth Crystal.

The chain crosses three disciplines — Blacksmith to Lv 78, Carpenter to Lv 78 and Goldsmith to Lv 78 — so no single class can finish it unaided.

All 7 raw materials are gathered, and one of them is time-gated: Gold Ore (9:00). That window comes round once per Eorzean day, every 70 real-world minutes.

Of the intermediates, Dwarven Mythril Ingot has the widest use: 168 recipes call for it, spanning seven of the eight crafting classes.