Aleksei sits next to 4 phonetic neighbors — Alexei, Aleksey, and Alexis are the closest matches by sound. Most share Aleksei's Russian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"defender of mankind"
"to heal, to cure"
"first among thinkers"
"beloved of God"
"son of the lion"
"the greatest, greatest one"
"devoted to Demeter, of the earth goddess"
"gift of God"
"devoted to Demeter"
"Christ-bearer, bearing the anointed one"
"consecrated to Mars"
"virtuous, without wickedness"
"virile, masculine, strong"
"gift of God"
"God is Lord (variant of Elijah)"
"gift from God, God given"
Similar sound: These names share phonetic patterns with Aleksei — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Aleksei.
Rhythm: Aleksei is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.