Alexei sits next to 5 phonetic neighbors — Alexis, Aleksei, and Alexey are the closest matches by sound. Most share Alexei's Russian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"defender, helper of mankind"
"God-like, comparable to God"
"white, silver (ancient root)"
"victory of the people"
"God is gracious"
"iron-willed, strong"
"gift of God"
"champion of the people"
"associated with Vladimir Lenin, revolutionary leader"
"proclaimer of peace"
"manly, brave, virile"
Similar sound: These names share phonetic patterns with Alexei — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek 'alexein' origins, giving them the same cultural heritage as Alexei.
Rhythm: Alexei is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.