Mythril Ring

Taken all the way down to base materials, one Mythril Ring is 2 crafting steps deep and needs 2 intermediates — Mythril Ingot ×1 and Siltstone Whetstone ×1 — which resolve to 2 distinct raw materials totalling 5 units, plus 15 crystals.

That bill outweighs 4,201 of the 13,602 recipes tracked here and 564 of the 2,216 Goldsmith ones, and 4,464 recipes nest deeper.

Only 8 of those crystals go into the final step; the other 7 are burned by the intermediates, so the real crystal cost is 8 Fire Shard and 7 Wind Shard.

The chain crosses two disciplines — Goldsmith to Lv 36 and Blacksmith to Lv 38 — so no single class can finish it unaided.

One intermediate outranks the result: Mythril Ingot is a Lv 38 Blacksmith recipe feeding a Lv 36 craft, so that step, not the last one, is the real gate.

Both raw materials are gathered, and no spot for either is timed, so nothing in the tree waits on the Eorzean clock.