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Finish the main quests "Find the Fifth Sage" and "Guidance from Ages Past."
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These tasks will grant access to the Sage of Spirit, Mineru, and the Spirit Temple, which houses the Ancient Blades.
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Drop down the hole in front of you at the Spirit Temple entrance.
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Proceed to the Spirit's Vessel, which is standing inside.
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There are two more Constructs around Mineru's Construct: a Smithing Construct and a Mining Construct.
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Head towards the Mining Construct on the right-hand side.
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When you interact with the Mining Construct, it will offer you Ancient Blades in exchange for Zonaite.
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