Llewellyn sits next to 4 phonetic neighbors — Llewelyn, Llewyn, and Lewin are the closest matches by sound. Most share Llewellyn's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"lion-like"
"immortal, divine"
"silver, bright, shining"
"handsome, beautiful"
"wolf counsel (from Ralph)"
"benevolence, humaneness"
"immortal"
"rejoice; pure"
"Craftsman; skilled tradesperson"
"son of Roderick"
"from the fort (place name origin)"
"wolf cub"
"westward, to the west"
"from Dyce, Aberdeenshire"
"red king"
"archer, warrior of the yew"
Similar sound: These names share phonetic patterns with Llewellyn — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh origins, giving them the same cultural heritage as Llewellyn.
Rhythm: Llewellyn is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.