The 10th day of the festival is Gavuseva.
On the previous night Ghantepoojari starts the story session about Pothraja and his heroism. This goes on late night. Before sunrise. they pray to Pothraja after which his power descends on two people who is the descendent of the Pothraja family. The people then start praising him for his amazing strength and warrior skills.
Then in order to pacify him, he is offered a black goat. Pothraja then sucks blood of the goat, thus pacifying him.
After this mangala arathi is performed.
This is called Gavuseva.
History of Pothraja:
Pothraja the king of Alarajapuri, was Known as UdthandaPothraja which means aggressive. He ruled an kingdom called 'Elu Sothina Kottai' (the seven walled fort). Pothraja The devotee of Lord Shiva was performing a yagnya to please the God and get the divine power. As a part of the yagnya, Pothraja has to offer 101 kings for sacrifice. 100 kings were already imprisoned for the sacrifice.
The story continues on these lines. Pandavas and Kauravas were given two kingdoms called Indraprastha and Hasthinapura respectively. But Kauravas had a Plan to destroy Pandavas and take over the whole kingdom so Kauravas sent Purochana to build a Wax house which gets destroy after some days. Then the Pandavas knowing this escaped into the forest nearby. Then on, they beseeched food and shared it amongst themselves. One of the Pandava brothers, Bheema was known for his mighty strength. But unfortunately food consumed was not sufficient to meet his hunger , So Pandavas said Bheema to make his own arrangement for his food.
One day Bheema with his great strength uprooted several trees and walked to the city to in order to sell them, Since it was dusk and feeling exhausted, he leaned the wood against the door of 'Elu Suthina Kottai' and went asleep. Unfortunately the wood which was leaned over the door due to its weight it was unable to withstand the weight of wood the door broke. Seeing the broken door and the mighty Bheema lying asleep the frightned soldiers complained to the king Pothraja. Pothraja came out and found the mighyty bheema fast asleep. Then he decided that Bheema would make the perfect 101th sacrificial king and had took him prisoned while Bheema was still asleep.
The Pandavas on finding their brother Bheema missing went to Lord Krishna for help. Lord Krishna using his divine power found that Bheema was imprisoned by Pothraja. Lord Krishna devised a plan to get Bheema out of the prison. He disguised Arjuna, another pandav brother as beautiful woman and settled down as Koravangis (bangle sellers) near the fortress.
As the news of this beautiful Koravangis spread all over the kingdom. Pothraja when came to know this he wished to marry the beautiful koravangi. Pothraja being ardent devotee of Lord Shiva was a pure against blood and meat, While the Koravangis were raw meat-eaters. But in order to marry this Koravangi by Pothraja he was led to fulfill the two conditions. They were Pothraja had to eat raw meat and set the 100 kings who were prisoners free.
Pothraja complied to both the conditions. As per the words between pothraja and Sri Krishna, Pothraja agrees to marry the girl thus setting Bheema free. Pothraja was then presented with an black goat from which he sucks the blood along with Bheema. . Now, Lord Krishna had to fulfil his part of the promise and gave Shankodari, the sister of Pandavas in marriage to Pothraja.
Gavuseva is performed in reference to Pothraja.