During the (meditation) practice of the generation stage, a practitioner (sadhaka) establishes a strong familiarity with the Ishta-deva (an enlightened being) by means of visualization and a high level of concentration. During the practice of the completion stage, a practitioner focuses on methods to actualize the transformation of one's own mindstream and body into the meditation deity by meditation and yogic techniques of energy-control such as kundalini (tummo in Tibetan). Through these complementary disciplines of generation and completion one increasingly perceives the pervasive Buddha nature.