Magnus sits next to 3 phonetic neighbors — Marcus, Maximus, and Angus are the closest matches by sound. Most share Magnus's Scandinavian cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"great"
"stern, strict, serious"
"noble friend, elf friend"
"bald (short for Calvin from Latin Calvinus)"
"the cleansing one"
"ruler of the world"
"from Scotland, a Scotsman"
"slender"
"woodland"
"high mountain, exalted"
"brave warrior (later folk etymology)"
"protector of people"
"staff of the Goths"
"chief desire"
"son of James"
"from the crooked stream"
"God is gracious"
"messenger, herald"
"bear"
"wolf lover"
Similar sound: These names share phonetic patterns with Magnus — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Magnus.
Rhythm: Magnus is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.