This study investigates the microstructural evolution and phase transformation mechanisms in Cr₃C₂–NiCr cermet coatings (Metco 5241 powder) plasma-sprayed onto S235 steel substrates. Two technologies were used: conventional atmospheric plasma spraying (APS) with radial powder injection (single-electrode A60 torch) and supersonic plasma spraying with axial powder feeding (HV-APS, three-electrode Axial III torch). The HV-APS coatings exhibited nearly two times lower porosity (6.16% vs. 11.99% for APS) and significantly higher microhardness (1141 HV0.2 vs. 897 HV0.2). Phase analysis revealed the disappearance of primary Cr3C2 and Cr21.26Ni1.74C6 carbides in favor of supersaturated Cr-Ni solid solutions. In erosion tests conducted at a 90° impact angle, the two coating variants exhibited nearly identical specific erosion rates (0.20 mg/g for APS and 0.19 mg/g for HV-APS) and comparable damage mechanisms, dominated by fatigue-driven lamellar spalling and brittle fracture. However, in tribological tests (ball-on-disc, 30 N load), HV-APS coatings showed nearly 27% lower wear volume (2.85 mm3) and a reduced specific wear rate (1.90 × 10-4 mm3/Nm) compared to APS (3.90 mm3 and 2.60 × 10-4 mm3/Nm, respectively), correlating with their higher density and hardness. The obtained results confirm that the use of axial powder feeding in supersonic HV-APS plasma spraying significantly improves the mechanical and tribological properties of Cr₃C₂–NiCr coatings, although this advantage is not evident in erosion tests at high impact angles.