He plays little part in the Arisen's quest, save as an annoying diversion - during the quest Come to Court he introduces the Arisen to court, whilst embarrassing them by placing a Jester's Cap on their head, and makes a brief and unwelcome appearance during Arousing Suspicion.
Feste if oft found either sitting in the Duke's throne, lying on the floor in a side room on the ground floor of the keep, or prancing up and down in the Dungeon, possibly tormenting inmates.
"Feste was born in a small farming village in Meloire, to a large family who worked the fields without rest. It was in no way an easy life. Because a male child could succeed the family name and would be a great aid to the farm once grown, Feste’s arrival was joyous and everyone showered love upon him. He was well cared for and even spoiled. However, after a number of years it became apparent that Feste was not a normal boy: he never appeared to grow any older. The family had no money for a doctor, so could only hope that his growth was simply slower than that of other people, but years later, Feste’s body remained that of a child. He could never help in the fields if he did not get any bigger, yet still had to be fed as much as anyone else. Additionally, being spoiled had made Feste a proud and arrogant boy. He threw tantrums if he did not get his meals on time, but made no effort to do any work himself. His birth now seemed a curse. One night, when their son was asleep, they looked down upon his childlike face and pressed a rag soaked in sedatives to it. Tears unchecked, they gave their son to the slave trader.
Feste was sold next to a troupe of players. Looking like a child, Feste was forced to become a jester, learning all sorts of tricks and skills as required. Amid these trials, Feste’s only wish was to gain an easy life and, relatively soon, he did exactly that. The answer he found was to gain the protection of one with power. He toadied up to the troupe leader and when performing, played his part for the nobles. He explained just how small and worthless a person he was, and praised the nobles for being so strong, so wonderful… Their egos salved, these powerful men and women took a liking to Feste and extended him their protection.
As one of the most popular performers, a request came from Duke Edmun of Gransys, asking for talented performers serve him in the castle. Feste wanted this more than anyone else. Feste’s ultimate desire was to gain the protection of those with true strength, get close to them, and live a life of comfort and ease. The duke had awesome power, making him the perfect target for this scheme. The troupe leader was afraid of earning Edmun’s wrath by sending less than their best performer, so Feste therefore began his days as the castle jester. However, this was still not enough to satisfy Feste. Once he learned of the factions within Edmun’s government that did not entirely agree with the duke’s rule, Feste quickly sidled up to the anti-Edmun elements and began to work informing those nobles of Edmun’s movements. When he heard of the increased activity of the organization Salvation, he next made contact with them and became their spy inside of Edmun’s territory. This indeed seems a rather lot of effort, more than was needed to survive, but it is all for Feste’s dream of an easy life. Thus he plies his wiles on all with power and uses them to his advantage, never once trusting another soul. Making use of everyone he can, and looking down on them all as he does, the jester Feste is a natural born trickster if ever there was one."
"Ah! The glorious return of the inimitable, the indomitable, the unforgettable... Scratch that last one. Who were you again?"
"I jest, fisher knight, for I am a jester. I daresay every man in Gran Soren knows who you are by now. Your fame is little wonder, at the fearsome rate you've solved the duchy's woes. The Arisen nods, they say, and lo the spheres do shake!"
"And now His Grace has you in his direct employ? Your rise to glory is an inspiration, humble, and no man looks up to you as much as I."
Feste is an obvious reference to the character of the same name from Shakespeare's comedy Twelfth Night; or, What You Will, and even shares the same role as jester/entertainer of the estate. (Wikipedia:Twelfth Night)
He also bears an uncanny resemblance to Tingle of the Legend of Zelda series.