Kaysen sits next to 5 phonetic neighbors — Jason, Mason, and Grayson are the closest matches by sound. Most share Kaysen's American English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"modern American creation"
"source of joy"
"son of Armand, warrior"
"true, faithful, genuine"
"God has helped"
"of the ancient Roman Cassia gens"
"manly, brave"
"deliverance of God"
"son of Otto"
"the cool one, refreshing wind"
"ruler of the home"
"modern coined name, son of Bray"
"ruler, sovereign (from Julius Caesar's name)"
"kingly"
"sea fortress, sea friend"
"from the valley town"
"healer (via Jason/Iason)"
"the herb sage"
"drawn out of water"
"famous spear"
Similar sound: These names share phonetic patterns with Kaysen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have American English origins, giving them the same cultural heritage as Kaysen.
Rhythm: Kaysen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.