Short answers, pulled from the story.
Arya is a Sanskrit and Pali term translated variously as noble, not ordinary, valuable, precious, pure, or rich. In Buddhist usage it designates those who have attained direct realization of emptiness and have entered one of the four levels of awakening, distinguishing them from puthujjanas, or ordinary worldlings.
Buddhist texts describe four levels: stream-entry, once-returner, non-returner, and arahant. Those who have attained any of these levels are called ariya puggalas, meaning Arya persons.
The Four Noble Truths are called the catvary arya satyani in Sanskrit, or cattari ariya saccani in Pali. The Noble Eightfold Path is called the arya marga in Sanskrit, or ariya magga in Pali. Both names use arya to signal that only those with noble wisdom fully understand these teachings.
Arya beings have had a direct realization of emptiness or selflessness and can see all types of suffering, physical and mental, gross and subtle, exactly as they are. Ordinary practitioners, lacking that direct realization, may still perceive some forms of suffering as desirable.
In Chinese Buddhist texts, arya is translated as the character 聖, pronounced sheng in Mandarin and sei in Japanese, carrying the meaning of holy or sacred.
The prefix Ayya, still used in many parts of South India as a respectful form of address when speaking to someone new, derives from the word Arya. It is used today as a courtesy term rather than a marker of spiritual attainment.