Herein, we report the synthesis and utilization of a new nanomaterial (gold nanobutterflies, GNBs). GNBs exhibit a butterfly-like shape including two concaves in the opposite sites of the NPs without a larger convex at the top and bottom. The complex shape was formed by combining solution additives that have been used in the field of protein science for the semi-quantified analysis of weak interactions in very complicated systems . Concave GNBs exhibit a similar size to those of immature droplets. The adoption of additive effects represents a universal methodology for discussing the formation pathways of other anisotropic gold nanomaterials. We also demonstrated the GNBs in the regulation of the formation/deformation dynamics of model LLPS droplets.