Chinese esoteric Buddhist practice was based on deity yoga plus the "3 mysteries": mantra, mudra and mandala. These 3 mysteries allow the Buddhist yogi to faucet into your body, speech and mind in the Buddhas.[100] Nirguna mantras, derived from historic Vedic texts, are older than any of your 3 forms. https://www.youtube.com/@AacharyaGoldieMadan/