Illyana sits next to 4 phonetic neighbors — Ilyana, Iliana, and Ileana are the closest matches by sound. Most share Illyana's Russian-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"bright, radiant"
"diseased (alternate Hebrew interpretation)"
"butterfly (by association with Vanessa genus)"
"pledged to God"
"noble, dear child"
"phonetic variant; no inherent lexical meaning"
"flowing river (associated meaning)"
"strong, enduring"
"exalted princess"
"map-maker, cartographer"
"light-bringer (when used as Lucia variant)"
"surname-derived given name"
"alluring siren of the Rhine"
"altar, hearth of God"
"defender of men (via Sandra/Alexandra root)"
"life"
"woman from Magdala"
"quartz crystal"
"new light, new star"
"serenity, harmony"
Similar sound: These names share phonetic patterns with Illyana — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Slavic origins, giving them the same cultural heritage as Illyana.
Rhythm: Illyana is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.