Cassiel sits next to 5 phonetic neighbors — Castiel, Gabriel, and Raphael are the closest matches by sound. Most share Cassiel's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"my covering is God; God protects"
"causing to forget"
"to gather, to assemble"
"shining, bright (via Hebrew Meir)"
"safe haven, shelter, refuge"
"friend, companion"
"son of Jack"
"auspicious, favorable"
"white"
"foot soldier"
"of gold, golden one"
"holy one (of Dewi/David)"
"gray, silver-haired"
"rejoice, be glad (via Gaius/Caio)"
"God is my justice"
"bold ruler, chief power"
"third"
"blameless and complete before God"
"ornament of God, God is my jewel"
"from the spring or well"
Similar sound: These names share phonetic patterns with Cassiel — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew origins, giving them the same cultural heritage as Cassiel.
Rhythm: Cassiel is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.