XYRIA originated on the Planet "Aronia" but is not Aronian, they are Kritian.
Kritians are a group of people with murderous intent towards Humans (mainly but also Aronians and other species) as to harvest their blood to help them grow their plants and with their magic.
Kritians are on the list of banished species and are to be allowed no chance to live.

XYRIA was captured by Jacen and his teacher, who brought XYRIA secretly into the Aronian city, where he gave Kyrie the task of teaching XYRIA their ways and hiding them away. (A choice he would later come to regret)

XYRIA is later blamed for Kyrie's death and captured by the royal guard for punishment which they escape and return to the Tree of Krite, where XYRIA was originally captured from.