Furious sits next to 4 phonetic neighbors — Julius, Darius, and Fabius are the closest matches by sound. Most share Furious's Latin-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"full of fury, fierce, passionate"
"the fifth"
"God is gracious"
"otter"
"flowing down, descending (Jordan River)"
"Supplanter; holder of the heel"
Similar sound: These names share phonetic patterns with Furious — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Furious.
Rhythm: Furious is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.