Thiana sits next to 4 phonetic neighbors — Tiana, Diana, and Thea are the closest matches by sound. Most share Thiana's Slavic cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"fairy queen; princess"
"twin, double"
"descendant of Cathach"
"song, melody, air"
"generous, covered with dew"
"open grassland, treeless plain"
"northeast wind"
"grace + God is my oath (Anna + Lisa)"
"grace, favor"
"wanderer"
"cushion, pillow"
"daughter of Andrew, brave"
"spring, bitter grace"
"calm as still waters"
"Bright one of the meadow"
"divine wisdom"
"beloved, eternal (via Amara)"
"beautiful, graceful"
"elf counsel"
"night beauty"
Similar sound: These names share phonetic patterns with Thiana — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have American/creative origins, giving them the same cultural heritage as Thiana.
Rhythm: Thiana is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.