Baldur sits next to 3 phonetic neighbors — Balder, Baldur, and Baldr are the closest matches by sound. Most share Baldur's Scandinavian cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"prince"
"one warrior, lone warrior"
"compassion of God"
"clear, luminous"
"a magical charm or spell; also a curse"
"poet, one who feels deeply"
"little ruler"
"the roarer, fierce storm deity (from Rudra)"
"modern invented name, possibly sun"
"modern invented name combining elements of strength and wisdom"
"From the city of Seville in southern Spain"
"immortal, deathless"
"outlaw, one who has been banned"
"Settlement near a rift or cleft in the land; from Old English rif (..."
"Inspired by the Japanese Kaizen philosophy meaning 'continuous impr..."
"to buy, to trade, merchant"
Similar sound: These names share phonetic patterns with Baldur — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Norse origins, giving them the same cultural heritage as Baldur.
Rhythm: Baldur is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.