When X'cirha began his adventure, he wanted to find his father. He eventually found out that he had not survived the Calamity, but meanwhile X'cirha had found a family - the Scions. After Dawntrail, X'cirha's goals are to find out more about the relic and maybe take the Scions to the First again.
X'cirha's childhood was, in a word, chaotic. Solus zos Galvus had a bounty on his head, so him and his adoptive dad went from place to place - dad was a sellsword. Among the people his dad worked for were Galuf Baldesion, Godbert Manderville, and the Tailfeather hunters. (pics: ages 6 and 11)
X'cirha has seen and destroyed several pieces of apparel, but by his time in Sharlayan, he has three outfits, one he uses most for traveling, his Ala Mhigan traditional tabard which he mostly wears in cities and for special occasions, and chainmail for when things get sticky.
X'cirha hides a crippling imposter syndrome under a "sunshine boy" façade, but he's genuinely kind and always tries his best to be a good part of his chosen family. He used to be afraid of anything and everything as a child, and sometimes he hardly realizes how strong and tough he is.
X'cirha was 16 when Carteneau fell, 21 when he joined the Scions of the Seventh Dawn, and is 24 at the time of the journey to Tural.
If someone asked about his striking feature, X'cirha would happily answer the white streaks in his hair - even if after Paghl'than he dyed them yellow in an "encourage Arenvald" gesture and after Ultima Thule he chopped off most of his hair to go under the radar.
So, this boy is X'cirha. He's supposed to be a Tia, but he also sometimes goes by Knyght - the surname of his adoptive dad. Both the Twin Adders and the Dragoons are more familiar with calling him Captain Knyght or Ser Knyght. Thancred and Y'shtola call him Kid. The Scions call him Cirha.