Spirit Alloy

Spirit Alloy is an intermediate crafting material - a refined product rather than a raw drop. Its in-game description calls it 'a special metal with spiritual properties', and it weighs 1 wt. Unlike most materials on this list, you make it rather than farm it.

The recipe is available from Level 13+, making it one of the earliest crafts in the game: 1 Dark Essence plus 2 Soul Essences. Both ingredients are common early-game currency-adjacent items, so the alloy effectively converts loose essences into a more specialized component.

Community documentation flags it 'for crafting usage', and the clearest documented consumer is the Invasion Bell, which can be crafted from a single Spirit Alloy (the alternative bell recipe uses 2 Dark Essences instead). Whether the alloy route or the raw-essence route is cheaper depends on your Soul Essence surplus - remember Soul Essences sell for a guaranteed 35 tokens each, so alloy-crafted bells carry a real opportunity cost. The Build Reset Token recipe also calls for 2x 'Dark Spirit Alloy', which appears to be a related refined material - pending verification on whether and how it derives from Spirit Alloy.