Mythril Saw

Taken all the way down to base materials, one Mythril Saw is 3 crafting steps deep and needs 3 intermediates — Mythril Ingot ×2, Mythril Rivets ×1 and Oak Lumber ×1 — which resolve to 2 distinct raw materials totalling 9 units, plus 25 crystals.

That bill outweighs 5,492 of the 13,602 recipes tracked here and 597 of the 1,932 Blacksmith ones, and 337 recipes nest deeper.

Only 9 of those crystals go into the final step; the other 16 are burned by the intermediates, so the real crystal cost is 18 Fire Shard, 4 Earth Shard and 3 Wind Shard.

The chain crosses two disciplines — Blacksmith to Lv 39 and Carpenter to Lv 32 — so no single class can finish it unaided.

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

Of the intermediates, Mythril Ingot has the widest use: 135 recipes call for it, spanning seven of the eight crafting classes.