Kaicen sits next to 5 phonetic neighbors — Kaysen, Casen, and Kaison are the closest matches by sound. Most share Kaicen's Multi-origin blend-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"sea/pure/rejoice (Kai) + son of (-sen)"
"people of the riverside forest"
"friend of horses"
"God is gracious"
"narrow channel (from Kyle)"
"beloved, dear"
"Christian, follower of Christ"
"strong man of God"
"gaming character: adventurous young explorer"
"Southern American place name as given name"
"excellent, fine"
"combination of ke- (prefix) and Marion (beloved)"
"descent, descending"
"an act of spiritual thanksgiving"
"from Kelso (place name)"
"from Arcadia, of the idyllic land"
"royal divine spark"
"modern coinage; possibly day-bright valley dweller"
"the American musical genre born in New Orleans"
"descendant of the peaceful one"
"son of Kel"
Similar sound: These names share phonetic patterns with Kaicen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Multi-origin blend origins, giving them the same cultural heritage as Kaicen.
Rhythm: Kaicen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.