Caius sits next to 5 phonetic neighbors — Kai, Gaius, and Cayo are the closest matches by sound. Most share Caius's Latin-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"to rejoice, joyful"
"charming, wily"
"spear, battle"
"bright, full of sunshine"
"prestige, luxury (cultural association)"
"stone clearing, rocky glade"
"remembered by Yahweh"
"see, a son is born"
"modern invented name"
"God supports, Yahweh supports"
"he gave, gift"
"yellow, golden"
"brave in battle"
"son of the south"
"free man"
"of, from (Dutch)"
"from Denmark, a Dane"
"God is gracious"
"gift"
"luminous circle, sacred light"
Similar sound: These names share phonetic patterns with Caius — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Caius.
Rhythm: Caius is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.