Mahabali Chakravarthi would have completed 99 aswamedha yaga. During the 100th yaga , vamana moorthi did avatara as Janardhana, took Trivikrama Roopa and have sent Mahabali to Suthala looka. In Pathala Looka Vamana moorthi would be the dwarapalaka of Mahabali for he being the grandson of Prahaladarajaru and a great vishnu bhaktha. He is one among the 16 Indra and would be the Indra of the next kalpa
Trivikrama Avatara in Kanchi
In order to attain Indra Padavi in next kalpa , Mahabali has to finish his 100th aswamedha yaga. Mahabali would have asked for a boon to see Trivikrama roopa again, as he was not able to see it before. In Order to do both things, Vamana moorthi in Suthala loka , takes a Snake form with 5 heads, makes a hole from Suthala Looka to Kanchi and Brings Mahabali with him.
Knowing this, DevaeIndra feared that he may loose his Indra Padavi. So he brought drought to the land, so that the Yaga may stop. Vamana Moorthi Takes the avatara of Cloud and brings rain to fill the ponds in kanchi, there by continuing the yaga. Finally after the finish of yaga , vamana moorthi takes Trvikrama avatara and sends Mahabali back to Suthala looka, there by ensuring that he will become Indra in next Kalpa.
Brighu Maharishi and Birth of Bhargavi
Brigu Maharishi goes to Kailasha and Brahma loka. As he did not get a welcome he deserved, he would give shapa to Shiva and Brahma. Next on visiting Vaikunta, Brigu Maharishi would do Padaprahara to Vakshastala of Paramatam. Lakshmi Devi would give shapa to Brigu Maharishi to be born as a normal human. Knowing this Paramatma would give shapa to Lakshmi Devi, that she should be born as the girl child to Brigu Maharishi, there by getting the name Bhargavi.
Brighu Maharishi would perform PutraKamaesti Yaga where Lakshmi devi would be born from the Yaga. This Yaga was performed in the exact place where Mahabali performed his 100th Aswamedha YAgna.
The same lakshmi devi would perform daily pooja to Lord varadharaja and would attain vaikunta. The Lakshmi devi in Varadharaja devastana is the Bhargavi born from Brighu maharishi Yaga.
the teertha in this temple is called Vamana teertha