Summoner ( Final Fantasy X ) In the world of Spira in " Final Fantasy X " , the title of summoner , is given to skilled magic users who have trained in the process of summoning powerful beings known as aeons . Summoners do this to defeat Sin , a powerful monster that periodically returns to devastate the world . Summoners also perform the sending , a dance ritual that sends the spirits of the dead to the Farplane lest they become fiends . Summoners are trained by the temples of the Yevon faith . List of Summoners . The summoners are presented in the order as they are introduced in " Final Fantasy X " and " Final Fantasy X - 2 " . " Story . The process of summoning relies on the control of pyreflies — the life energy of Spira — manifesting them into a corporeal form of the fayth ' s imagining . This is how aeons , Dream Zanarkand and Sin are all formed . After completing their initial trial , each summoner undertakes a pilgrimage to the temples of Spira to gather aeons and develop their strength in body and mind . Acquiring an aeon from a fayth is a fatiguing process , as the summoner must have a strong mental bond with the fayth to be able to call forth its aeon . At the end of the pilgrimage the summoner receives the Final Aeon from Lady Yunalesca at Zanarkand Dome and is ready to fight Sin . The summoner who defeats Sin sacrifices his or her life to perform the Final Summoning and is posthumously granted the title of high summoner . High summoners are worshiped by the followers of the religion of Yevon . The practice of summoning goes back to at least 1 , 000 years to the days of Zanarkand , and thus precedes the faith of Yevon . As told in " Final Fantasy X - 2 . 5 ~ Eien no Daishō ~ " , summoners used to live on Besaid Island a thousand years ago during the time of the Machina War between Bevelle and Zanarkand . Summoners were described as those with an enhanced sensitivity to pyreflies , trained to fight against Zanarkand , perhaps used to conjure magical weapons or creatures to aid in battle , while living a life of suppression regardless of their own desires . Summoners took the name of a deity worshiped before Yevon became the main religion in Spira , and once they died or became an unsent , they gave up that name , reverting to their original name with another succeeding the god ' s name . The Yevon faith arose to give people hope after the Machina War and Sin ' s emergence . Sin was going on a rampage all across Spira , destroying every machina city , and thus a religion arose that abhorred the use of machina , and spread the message of atonement as a means of freedom from the world ' s cursed state . Lady Yunalesca , summoner Yevon ' s daughter , used the Final Summoning to destroy Sin , and although it returned after a time , the religion of Yevon was formed to revere the Final Summoning , hailing it as the only means of vanquishing Sin . However , if the Spirans would not atone for their sins , Sin would always return . Summoning thus became a practice promoted by Yevon and the old summoning practices of adopting a name of a deity and creating one ' s own fayth for summoning faded . Fayth from before the Machina War were gathered and placed in the temples of Yevon to train summoners , and new fayth were also created specifically for this purpose . Summoners became revered among the faith as the beacon of hope , the only ones able to free Spira from Sin . To become a summoner , one must train meticulously under the care of the temples and only a few succeed in graduating into a full - fledged summoner . Before Yuna ' s pilgrimage only five summoners in the past 1 , 000 years have defeated Sin : Lady Yunalesca , Lord Gandof , Lord Ohalland , Lady Yocun , and Yuna ' s father , Lord Braska . Other summoners appearing during Yuna ' s journey include Maester Seymour , Isaaru , Lady Dona , Lady Belgemine , Father Zuke , and Lady Ginnem . Yuna sets out to her own pilgrimage but along the way discovers Yevon ' s corrupt ways . Upon meeting the unsent Lady Yunalesca , Yuna discovers that the Final Summoning requires one of her guardians be made a fayth for the summoning , and if the bond between the guardian and the summoner is strong enough , together they can destroy Sin . However , Sin is but an armor for Yu Yevon , a parasitic being that exists only to summon and the remains of the legendary summoner Yevon the Yevon faith is named after , who will possess the Final Aeon and transform it into the new Sin , thus perpetuating the millennium - long spiral of death . Upon learning of this Yuna rejects the Final Summoning as false hope . Yunalesca explains that false hope is the best Spira has , as Sin is eternal , and that summoners are glad to give their lives to stop Spirans for succumbing into despair . Yuna disagrees , saying her father didn ' t die for false hope , but because he had believed he could free Spira . Yunalesca tries to kill Yuna and her guardians for rejecting the teachings of Yevon and to free her now that she has — in Yunalesca ' s eyes — lost the only hope she had . Yuna and her guardians prevail and kill Yunalesca , thus ending the tradition of Final Summoning for good . Upon hearing of this the Grand Maester of Yevon , Yo Mika , sees the temples and their teachings have become obsolete and departs to the Farplane willingly . Yuna and her guardians tackle Sin head - on by attacking it on the Al Bheds ' airship and then traversing its innards until they come upon Braska ' s Final Aeon . Defeating the Final Aeon , Yu Yevon emerges ready to possess the next aeon , but Yuna ' s party destroys it . The summoning halted , Sin explodes . When Sin is destroyed , the fayth are freed from their burden and choose to disappear from Spira . As the beliefs in Yevon ' s teachings wane , summoners — who can no longer call forth aeons — become increasingly obsolete as much of the population looks toward a new , and different , future . Origin . Summoners in " Final Fantasy X " bear many conceptual similarities to the traditional Japanese " " . Traditionally , miko are female shrine maidens who offered numerous services in the past , including divination , prayers , and herbal medicine which was , in that time period , considered magical . In desperate times when the shrines and temples were short of funds they would occasionally provide funding through prostitution . Most importantly , " mikos " were called upon to perform ceremonial dances , some of which were meant to drive away evil spirits and protect the shrine . The idea of dancing to ward off evil spirits in particular could roughly be used to describe the sending .