Trystan sits next to 4 phonetic neighbors — Tristan, Tristen, and Tristin are the closest matches by sound. Most share Trystan's Welsh cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"tumult, noise of battle"
"possibly related to Old Norse Olaf (ancestor's relic)"
"of the forest men, from Norman Freselier"
"emperor"
"his peace"
"king"
"God has heard (via Sam = Samuel)"
"divine being, eternal one"
"son of Hugh"
"traveler’s peace, peaceful territory"
"spiral, coil"
"God is gracious"
"counsel, chief"
"elf ruler"
"resolute protector"
"bold place, wild one"
"famous land"
"gaming character: adventurous young explorer"
"descent, to descend"
"son of, awakening"
"Yahweh is my light"
Similar sound: These names share phonetic patterns with Trystan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Celtic 'drest' origins, giving them the same cultural heritage as Trystan.
Rhythm: Trystan is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.