Rhysand sits next to 4 phonetic neighbors — Rhys, Tristan, and Lysander are the closest matches by sound. Most share Rhysand's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"ardor, enthusiasm (from Welsh Rhys)"
"from the gray hill"
"strong flow, powerful surge (river etymology)"
"modern invented name"
"descendant of Cathasach"
"of the forest, from the wood"
"Son of Nils (Neil); son of the champion"
"heart, mind (from Hugh root)"
"healer"
"new house"
"peaceful ruler"
"Son of Otto"
"from the Afton river"
"powerful ruler"
"thorny shrub, wild rose"
"royal power"
"word of God"
"one of high authority, master"
"modern American compound name"
"from the town by the sea"
"thankful, God has heard"
Similar sound: These names share phonetic patterns with Rhysand — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh Rhys + invented -and suffix origins, giving them the same cultural heritage as Rhysand.
Rhythm: Rhysand is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.