Markel sits next to 3 phonetic neighbors — Marcel, Marcus, and Markell are the closest matches by sound. Most share Markel's Spanish-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"of Mars, warlike"
"immortal, divine"
"round, barrel"
"purple gemstone (jacinth)"
"defender, advocate"
"enduring, steadfast (via Dante)"
"chosen, elected, the elect"
"of the moon, lunar"
"son of Jan (John)"
"gift of God"
"short form of Trevor meaning large homestead"
"defender of men"
"Dack's settlement"
"sheltered bay, cove"
"friend, darling"
"dark one's town"
"thunder"
"healer"
"Carl's town or farm"
"nature name: rivers, waterways"
"the koa tree (strength)"
Similar sound: These names share phonetic patterns with Markel — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Markel.
Rhythm: Markel is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.