Dylann sits next to 3 phonetic neighbors — Dylan, Dillon, and Dillan are the closest matches by sound. Most share Dylann's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of the wave, born of the sea"
"chief, ruler"
"God is gracious (via Sean/John)"
"little warrior"
"handsome, beautiful"
"western settlement"
"new house, new home"
"moonlit, bright moon"
"sun, throne"
"God has heard"
"one who bakes bread"
"archer, warrior of the yew"
"one who tucks/stretches cloth"
"joyful"
"elf friend, friend of the elves"
"beloved"
"westward direction"
"variant of Braylen or Graylen"
"invented modern name"
"calf, heifer (symbolic gentleness)"
Similar sound: These names share phonetic patterns with Dylann — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Welsh mythology origins, giving them the same cultural heritage as Dylann.
Rhythm: Dylann is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.