Dear Gilbert,

Thank you for your question. In order to practice tantra, especially higher tantric practices such as Yamanataka, it is considered necessary to study under a qualified guru whom you have received the relevant empowerment and commentary in person. Depending on the type of initiation, the ceremony can actually take up to two to three days for the higher practices, and would involve your active participation. However, depending on the instructions from the guru, other forms of initiation can also be used, as long as they have authorised it. As you have taken Garchen Rinpoche to be your guru, you should contact him or his centres to find out more about the lineage of practice, the corresponding sadhana texts, and to clarify the vows and commitments associated with the practice.

As for reciting the mantra of deity alone, this would not actually be considered a complete sadhana of that deity. This is because for a sadhana to be complete, it is said that it should have include seven parts, known as the seven limbs, if not more. These seven are: Prostration (inclusive of taking refuge and generating bodhicitta), making offerings, confession downfalls and shortcomings, rejoicing, requesting teachings, beseeching, and finally dedication. Together with these prayers we engage in mantra recitation.

Mantra recitation, even though immensely powerful, is not considered a sadhana. Sadhana necessarily include prayers such as the seven limbs mentioned above, and also include accompanying visualisations. For higher tantric practices, these visualisations are very complex. The sadhana is engaged in daily to achieve the desired results, for example complete enlightenment.

Coupled with this is the movements of the psychic winds within the body, which is brought about through the various visualisations, prayers and mantras contained within a sadhana. This is main purpose of tantric practice. Utilising these winds we are able to achieve higher states in our meditations and ultimate achieve enlightenment.

This does not mean that the mantras do not have any power. On the contrary, mantras are the Buddhas embodied in the form of sound. Therefore, they are very powerful. His Eminence the 25th Tsem Rinpoche has given an excellent teaching on mantras, which you can watch here: https://www.tsemrinpoche.com/tsem-tulku-rinpoche/buddhas-dharma/mantras-holy-words-of-power.html. You can definitely gain attainments through the recitation of mantras, but they will be more effective if combined with other prayers and practices. I hope this answers your question about mantras and sadhanas.

Thank you