Obsidian sits next to 3 phonetic neighbors — Sebastian, Octavian, and Oberon are the closest matches by sound. Most share Obsidian's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"volcanic black glass"
"modern invented American name with no traditional etymology"
"rock, stone"
"dark one, dark-haired"
"wild boar hunter"
"diminutive of Hobart"
"who is like God? (rhetorical, meaning no one)"
"mighty ruler with good counsel"
"hill covered with broom, steep hill"
"God sows, God scatters seed"
"manly warrior ruler"
"helper, protector"
"of Zeus, belonging to Zeus"
"to sing, to shout (via Jaron/Yaron)"
"deep valley dweller"
"father of peace"
"son of the devotee of Saint Faolán"
"arhat, enlightened Buddhist monk"
"great, kingly"
"strength, permanence"
"bright-headed"
Similar sound: These names share phonetic patterns with Obsidian — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Obsidian.
Rhythm: Obsidian is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.