Arwyn sits next to 3 phonetic neighbors — Arwen, Erin, and Bronwyn are the closest matches by sound. Most share Arwyn's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"very fair, noble maiden"
"meadow, woodland clearing"
"God enlightens"
"beautiful friend"
"life, to breathe, to live"
"vine, climbing plant (via Latin liana)"
"field of gold"
"princess, noblewoman"
"flowing, ease"
"strong noblewoman"
"close companion of the heart"
"invented blend of Nash and Ashley"
"from the gray lands"
"God is my refuge"
"noble woman of the Aryan people"
"Botolph's stone, settlement by the forest"
"pure, free (khalī in Arabic)"
"light, bringer of light"
"gracious gift"
"hunter's meadow"
"reborn"
Similar sound: These names share phonetic patterns with Arwyn — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh origins, giving them the same cultural heritage as Arwyn.
Rhythm: Arwyn is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.