Alys sits next to 5 phonetic neighbors — Alice, Alyse, and Alexis are the closest matches by sound. Most share Alys's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"noble kind, of noble birth"
"blind, sixth (via Cecilia)"
"work, labor, vigor"
"sea, ocean"
"A Messianic title; place where the Ark of the Covenant rested"
"descendant of Raghallach"
"son of John, God is gracious"
"crimson, dark red"
"pearl"
"living, vital"
"life"
"bitter grace, beloved"
"precious green gem"
"chamber, room"
"grace, favor of God"
"combination of cherry and beryl"
"twin"
"emerald lake; sparkling green water"
"estate of the fifth son"
"holly tree"
Similar sound: These names share phonetic patterns with Alys — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic via Old French origins, giving them the same cultural heritage as Alys.
Rhythm: Alys is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.