We perform point-particle direct numerical simulations(PP-DNS) of particle-laden flow through a linear compressorcascade subjected to synthetic freestream turbulence. Monodisperseparticles are advanced in a one-way coupled Eulerian-Lagrangian framework with drag-only dynamics. We quantifyblade-particle collisions and resulting blade erosion based onhigh-fidelity data, and the erosion hotspots are predicted near theleading edge and over the pressure side. On the pressure side,for intermediate Stokes numbers, the onset of collisions correlateswith elevated boundary-layer intermittency associated withbypass transition, whereas for larger particles impacts occur fartherupstream with a higher probability of multiple rebounds. Onthe suction side, sparse collisions appear only for the smallestparticles and are phase-modulated by separation-induced vortexshedding. Joint distributions of impact velocity and angle showthat leading-edge impacts are faster and span wider angles thanpressure-side impacts, explaining their greater erosive severity.The present results highlight the role of unsteady boundary-layerdynamics in affecting erosion in compressor cascades