Darksteel Buckler ★★

Taken all the way down to base materials, one Darksteel Buckler is 3 crafting steps deep and needs 4 intermediates — Darksteel Ingot ×1, Darksteel Plate ×1, Darksteel Rivets ×1 and 1 other — which resolve to 2 distinct raw materials totalling 27 units, plus 27 crystals.

That bill outweighs 9,763 of the 13,602 recipes tracked here and 962 of the 1,441 Armorer ones, and 337 recipes nest deeper.

Only 2 of those crystals go into the final step; the other 25 are burned by the intermediates, so the real crystal cost is 21 Fire Crystal, 3 Ice Crystal, 1 Earth Cluster and 2 other kinds.

The chain crosses two disciplines — Armorer to Lv 50 and Blacksmith to Lv 50 — so no single class can finish it unaided.

1 of the 2 raw materials come out of the ground, and one of them is time-gated: Darksteel Ore (1:00). That window comes round once per Eorzean day, every 70 real-world minutes.

Of the intermediates, Darksteel Nugget has the widest use: 121 recipes call for it, spanning seven of the eight crafting classes.