Complex sentence: The Three Vajras are often employed in tantric sadhana at various stages during the visualization of the generation stage, refuge tree, guru yoga and yidam, or meditational deity, processes.
Split into simpler sentences: The Three Vajras are often employed in tantric sadhana at various stages during the visualization. For example the Three Vajras imagery may be used during the refuge tree, guru yoga and yidam, or meditational deity, processes.