Aizen sits next to 4 phonetic neighbors — Aiden, Jason, and Hazen are the closest matches by sound. Most share Aizen's Japanese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"love and goodness"
"son of Aodh (fire)"
"swiftness, fleetness"
"all wise (from Norse Alviss)"
"sea warrior"
"crowned with laurels, victorious"
"from the marshy plain"
"earth"
"little hawk or blackbird"
"tournament fighter"
"son of John"
"brave in power"
"Gomeric's mountain, power mountain"
"fisherman"
"from the isle"
"admirable, worthy"
"king's meadow, king's clearing"
"dark settlement"
"shepherd, one who tends sheep"
"of noble renown"
"slender, narrow"
Similar sound: These names share phonetic patterns with Aizen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Japanese origins, giving them the same cultural heritage as Aizen.
Rhythm: Aizen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.