Agni is the cosmic fire described in the ancient Rig Veda. It is the first word of the first verse, the force that causes the world to come into being, the outward stroke.
Agni has also been associated with the light of consciousness and the sense of sight. It is the digestive fire. It is sometimes represented by the sun and with the masculine.
Soma or nectar is the softener and refiner, it is the ocean of the Divine Mother’s milk that draws us within, the inward stroke. The moon is sometimes called soma, and it’s affiliated with the feminine.
We are immersed in that ocean of soma in its raw form. Our physiology is designed to refine soma into a form that laws of nature can use. With a practice that enlivens consciousness, transcendence is the trigger for refining soma. Once refined, it becomes available to the laws of nature, enhancing their quality of life and skills. This amplifies their ability to support us. Soma also cultures sattva. Sattva refines the senses, allowing the God Consciousness stage and the refined stages to unfold.
The key as always is balance. Too much agni and it burns. Too much soma and it dissolves (although the latter is rare).
The Yoga Vasishtha says balanced agni and soma in our physiology leads to balanced breath (prana or life force), integrated enlightenment, and special abilities.
The Rig Veda, first and core of the Vedas, explores both. Its 9th Mandala (book, of 10) is sometimes called the soma mandala as it talks extensively on this topic.
I’ve since come to see the power of Shakti as what drives Agni. As soma is from Mother’s ocean, we can see both come from the Divine Mother.