The below note is neither meant as a sectarian effusion nor a historical account. It is a hagiography and just that.
sarva-bhUtAmakaM manmanobodhakaM sat-kR^ipAsAgaraM devasenApate pAhi mAM pAhi mAM pAhi mAM deva tubhyaM namo deva tubhyaM namo deva tubhyaM namaH ||
The shrI-vaiShNava AchArya, sudarshana sUrI, was proceeding to shrIperaMputtur after visiting the old temple of viShNu at venkaTagiri (not Tirupati) and consecrating a shalagraman there. On his way back on his horse cart he had to pass by the shrine housing the great vAyu li~Nga of the terrible rudra, kAlahasti. rudra’s presence was felt here in the form in which he had destroyed gajAsura. The zealous vaiShNava who did not recognize the greatness of The god, asked his henchmen to draw the curtains in his cart and he closed his eyes so that even by error he might not cast his eyes on the shrine of rudra. When he was a safe from kAlahasti distance he opened his eyes but to his horror he had turned blind. Shocked he uttered the verse:
sarvAtmatA te shrutiShu prasiddhA satyaiva sA kAlakarIsha nUnaM |
apashyatastvA madhunA samastaM yato na me dR^iShTipathaM prayAti ||
He was constantly tormented by bhUta-s and agents of sharabha. He recalled the great vaiShNava tantric, the master of pA~ncharAtra prayoga, rAma deshika and wanted to seek his aid. That night he had a dream that shri rAma deshika had already attained mokSha but he appeared in his dream and asked him to seek the aid of his illustrious student, the accomplished tantric shri rAmAnuja deshika. He met rAmAnuja deshika at Tiruttani who performed an appropriate rite to release sudarshana from the grip of rudra’s wrath, even as viShvaksena was brought back to life by kAla bhairava, when he had drunk viShNu’s blood from the skull-bowl fashioned of brahmA’s severed fifth head.
rAmAnuja deshika, was born in kA~nchipuraM in family of devote vaiShNava brAhmaNa-s of the ubhaya vedAnta stream who regularly sung the DP4000 and lit lamps at viShNu shrines. rAmAnuja was a natural poet and mastered kAvya and alaMkAra at an early age in addition to the study of the taittirIya school of the yajur veda. He then proceeded to study the mantra shAstra with the great tantric guru rAma deshika who had mastered the entire lore of pA~ncharatra mantras. Having initiated rAmAnuja into all of them he asked him to perform purashcharaNa of the 104 mighty astra mantras of viShNu, which leads one to highest pA~ncharAtric siddhi. In order to do this he proceeded to a desolate spot near Tiruttani where he began his japa in seclusion. One day as he was wandering in the forests of the Nagari hills he saw mysterious vaikhAnasa brAhmaNa wearing a yellow dress. The brAhmaNa saw him but did not speak anything but merely gestured to him the way kApAlika’s do. That night he had a dream in which kumAra communicated to him the bagalAmukhi vidyA-s. He did japa of those mantras and attained siddhi — he had become the master of the sAmkhyAyana tantraM. Then that same brahmin came by and asked him to accompany him to Tirupati. As they were ascending the slopes to have a view of the great nArAyaNa, the brahmin gave him two mighty mantra-s, that of the goddess trailokya-vijayA (along with its saMputIkaraNa for the mantra of vilistengA) and viShNu trailokyamohana. Then he asked him to proceed to Bellary after having seen the image of the deva on Tirumala.
As rAmAnuja was proceeding to Bellary a jaina mantravadin attacked him with the mantra of kurukullA, but he retaliated with the trailokya-vijayA spell and destroyed the jaina’s entire mantra bala. rAmAnuja passed through to Bellary which was in a precarious condition due to the ravages of the green-robed, bearded, ruffianly Meccan demons. Here, after he had finished his mantra japa, he suddenly saw an apparition of the great war-god kumAra, with six heads wielding several terrifying weapons. He spontaneously composed two poems to kumAra in the daNDaka and bhuja~Nga meters. At that point he met the last kaumArAchArya of the va~Nga lineage (from what is now in the terrorist state of Bangladesh), kumAra-guru , who gave him all the kaumAra mantras. He instantaneously attained the siddhi of all but two, which are the most secret – the krodha-kumAra mantra and vkR^itagraha mantra.
He was asked to go to nAgArjunakoNDa and perform their japa. As he was performing the purashcharaNa he saw the dreadful skanda appearing with a single head and he uttered a 4-syllabled mantra. That mantra became varAha, who held in his hand a great sword dripping with the blood of hiraNyAkSha, with an upavIta of 3 intertwined snakes. Then from the snout of varAha emerged that awful emanation of kumAra, krodha-rAja kumAra, with 6 heads, who is irresistible. With these mantra-s he had attained the height of tantric perfection, he was called a deshika. He was the master of the kaumAra lore, an impregnable mantra-vAdin. After his marriage he was proceeding with his wife to kumAra parvata when he was attacked by the turuShka-s on the way who tried to seize his wife. He deployed the krodha-rAja ShaNmukha hR^idaya mantra and got ready to fight them with his small band. The mahAshUla of kumAra entered his weapons and they killed 80 turuShkas sending the rest scampering over the country side. Having reached kumAra parvata he installed himself there for worshiping the deity.