The western North Pacific Subtropical Gyre (wNPSG) is a typical oligotrophic region where nutrient supply to the surface ocean is strongly limited. Cyclonic eddies (CEs) can uplift isopycnals and shoal the nutricline, while typhoons can modulate eddy evolution and enhance vertical mixing. However, how typhoon forcing modifies nutrient distribution and diapycnal transport within a CE remains insufficiently constrained by direct observations. In this study, we examine this issue by tracing a mature CE in the wNPSG before and after the successive passages of typhoons Toraji and Usagi in November 2024, using hydrographic, nutrient, turbulence, and remote sensing data. The observations showed that the CE underwent post-typhoon structural reorganization with the core sea level anomaly increasing from -0.17 to -0.15 m, mean eddy amplitude increasing from 0.13 to 0.17 m, and effective radius expanding from 189 to 229 km. Meanwhile, following typhoon passage, dissolved inorganic nitrogen (DIN) concentrations became detectable in the upper ~80 m, where it had been largely below the limit of quantitation before the typhoon, suggesting that post-typhoon CE reorganization was accompanied by changes in upper-ocean nutrient distributions. Mean diapycnal DIN flux at the base of the euphotic zone in the CE also increased from 3.43 ± 4.22 to 5.31 ± 5.12 μmol m^-2 d^-1, indicating strengthened upward nutrient supply. However, upper-ocean N:P ratios of 0.31 - 1.39, despite enhanced DIN availability associated with typhoon forcing and CE dynamics, remained far below the Redfield ratio of 16, demonstrating persistent N limitation in the wNPSG. These findings highlight the importance of typhoon–eddy interactions in regulating nutrient distribution and supply in oligotrophic oceans.