Trema Tremais a non - player character from " Final Fantasy X - 2 " who can be investigated through a sidequest in Via Infinito . Trema was the leader of and founder of New Yevon . He can become a party member in the International and " HD Remaster " versions . Profile . Appearance . Trema is an old man dressing in a ripped Yevon priest outfit . He is fast and agile , despite his age . He shares the same model as the unsent priest in Zanarkand Dome in " Final Fantasy X " . Story . In the two years after Sin ' s defeat , Trema , a former denizen of Yevon , wished to learn more about Spira ' s history , hidden all over the world in the form of spheres . He created sphere hunting , which soon became a popular craze among young people , and began searching Spira for lost spheres . Trema founded New Yevon to bring stability back to Bevelle and those people who had fallen out of touch . Unbeknown to everyone , however , Trema was an unsent who had falsified his title as an " Unaffiliated Yevon Priest " to infiltrate the heart of Yevon . Trema ' s true objective for having people collect spheres was not to " find the truths of Spira " , but to erase the past . He took over the Monster Arena from Lord Mi ' ihen ( who had founded it 800 years ago ) to carry on his aspirations of using the facility to train the Crusaders . Trema observed that whenever Sin was defeated , the Crusaders , who now had nowhere to use their training , sought conflicts , which caused him great despair . He surmised that what they needed was not physical , but spiritual training and labeled himself a Yevonite , began urging people to " pursue the truth " ( through sphere hunting ) and founded New Yevon . As his philosophy was that " people must rid themselves of the past to become stronger " , Trema took the spheres New Yevon had gathered and destroyed them in the depths of Bevelle in a place called Via Infinito , his rationale being that people must discard the past to face the future . Trema never resurfaced , and New Yevon elected a chairman who continued the good work Trema had begun , unaware their founder was still in the Via Infinito where he , as a powerful unsent , was able to control even the mightiest of fiends . The Gullwings venture into the Via Infinito and upon reaching the final cloister and defeating Paragon , Trema appears and dispatches the fiend before challenging the party . Paine theorized that even though Trema entered the Via Infinito a year before their arrival , he may have been dead and unsent long before his descent into the cloisters . Gameplay . Creature Creator . Trema can be recruited into the party through the Creature Creator once defeated in the International and HD Remaster versions of " Final Fantasy X - 2 " . He fights roughly the same as he does during his boss battle , though the speed of his attacks is nearly doubled . Boss . Trema is the most difficult enemy in " Final Fantasy X - 2 " and is fought in the depths of the cloisters in Via Infinito . He is regarded as the game ' s superboss . Creation and development . Voice . His English voice actor is David Rasner , who also provides the voice for Brother . Musical themes . " New Yevon Party " plays during the battle against Trema .