Exarchic Tower Shield ★★★★

Taken all the way down to base materials, one Exarchic Tower Shield is 2 crafting steps deep and needs 3 intermediates — Duraluminum Ingot ×1, Grade 4 Vitality Alkahest ×1 and Solstice Ingot ×1 — which resolve to 8 distinct raw materials totalling 19 units, plus 24 crystals.

That bill outweighs 7,589 of the 13,602 recipes tracked here and 733 of the 1,441 Armorer ones, and 4,464 recipes nest deeper.

Only 6 of those crystals go into the final step; the other 18 are burned by the intermediates, so the real crystal cost is 6 Earth Cluster, 6 Fire Cluster, 3 Ice Cluster and 3 other kinds.

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

4 of the 8 raw materials come out of the ground, and 3 of them are time-gated: Dolomite (8:00, 20:00), Hard Water (4:00, 16:00) and 1 other. The widest gap between consecutive opening times is 6 Eorzean hours, about 18 real-world minutes.

Of the intermediates, Solstice Ingot has the widest use: 39 recipes call for it, spanning six of the eight crafting classes.