Phenix sits next to 3 phonetic neighbors — Phoenix, Felix, and Venice are the closest matches by sound. Most share Phenix's French-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"immortal bird that rises from ashes"
"little bear, she-bear"
"pledged to God"
"noble lady, bread-kneader"
"woodland clearing at the brink/edge"
"old stone place"
"lurking rock, murmuring rock"
"wild mountain goat, ibex"
"of the tower"
"valley waterfall"
"slender, fair"
"one who charts new territories"
"Rose; from the flower rosa"
"stag clearing, deer meadow"
"little love, sweetheart"
"beautiful"
"plum tree (as Chinese surname 李)"
"diseased (alternate Hebrew interpretation)"
"dew of the sea"
"oak tree (via Ayla)"
"peace, fruitfulness"
Similar sound: These names share phonetic patterns with Phenix — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Phenix.
Rhythm: Phenix is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.