In the Gaura-ganoddesa-dipika (74) it is said that Nakula Brahmacari displayed the prowess (avesa) and Pradyumna Brahmacari the appearance (avirbhava) of Sri Caitanya Mahaprabhu. There are many hundreds and thousands of devotees of Lord Caitanya among whom there are no special symptoms, but when a devotee of Lord Sri Caitanya Mahaprabhu functions with specific prowess, he displays the feature called avesa. Sri Caitanya Mahaprabhu personally spread the sankirtana movement, and He advised all the inhabitants of Bharatavarsa to take up His cult and preach it all over the world. The visible bodily symptoms of devotees who follow such instructions are called avesa. Srila Sivananda Sena observed such avesa symptoms in Nakula Brahmacari, who displayed symptoms exactly like those of Sri Caitanya Mahaprabhu. The Caitanya-caritamrta states that in the Age of Kali the only spiritual function is to broadcast the holy name of the Lord, but this function can be performed only by one who is actually empowered by Lord Krsna. The process by which a devotee is thus empowered is called avesa, or sometimes it is called sakty-avesa.