We demonstrated for the first time a triple-level operation of a resistive-gate Flash (RG-Flash) on a FinFET platform. Comprehensive reliabilities have been examined. The results show the forming-free property, low programming (PGM) current (<0.1uA), and ultra-fast PGM time (<10ns), enabling extremely high active energy efficiency, 3 fJ/switching. Furthermore, a multi-level capability featuring a 3-bit-per-cell (8 levels) operation has been demonstrated successfully. We have also achieved more than 105 cycles endurance and excellent data retention for each level in 125°C for over one month. The array-level reliability is also evaluated, showing well disturbance-immune during SET/RESET, no sneak-path issues, which keep healthy signal-to-noise margin, with window= 10x between two levels, even if the array is expanded to 1 million-cells size. This work provides a strong candidate for the next generation Flash with resistive switching and CMOS process compatibility.