Cyril is an original character created for Legendary Guardian and has no basis in cannon from Square Soft in Final Fantasy X. He appears, or is mentioned briefly, in several chapters of LG.

When we first encounter Cyril, he is a member of the Bevelle guard. He is the member of the foursome that attempts to block Auron's Uncle, Youke, from entering the Trials of Bevelle without a Summoner. After finding it impossible to stop Youke, the young warrior monk casts several spells and uses a potion in an effort to assist the older man and former Second of the Bevelle Guard.

Later, Cyril is mentioned again. He has, at that point, been elevated to the position of Second of Bevelle. He is brought up in conjunction with Auron's return to Bevelle at age 23. When Auron requests transfer from his post in Djose to the Bevelle garrison, we learn of Cyril's elevation. Later, it is Cyril's death that becomes one of the two major catalysts for Auron's Censure at the hands of the Lord High Priest of Bevelle, Inek.

Aside from his being young, a monk, and a member of the Bevelle guard, you will find no specifics in LG about Cyril. However, in my mind he is about five foot eleven inches, a brunette with brown eyes, and of non-descript Caucasian skin tone. His preferred weapon is the long sword though, like all monks in LG, he is trained in the use of almost every weapon but machina during his years in the temple. He was thirty-four at the time of his death.