Arcaius sits next to 3 phonetic neighbors — Arcadius, Lucius, and Cassius are the closest matches by sound. Most share Arcaius's Greek-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"from Arcadia, of the idyllic land"
"spiral, coil"
"God is gracious"
"healer (if from Greek Galen)"
"pure, innocent"
"divine being, eternal one"
"great chief, mighty lord"
"exalted one (via Aaron)"
"warrior's town"
"descendant of Creadan"
"little one, junior (Vaughn element)"
"free man"
"praise (from Hallelu)"
"God is gracious"
"ship's structural backbone"
"brave, vigorous power"
"follower of Dionysus (god of wine)"
"who is like God?"
"the new house"
"slender, narrow one"
Similar sound: These names share phonetic patterns with Arcaius — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Arcaius.
Rhythm: Arcaius is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.