Raiden sits next to 4 phonetic neighbors — Ryden, Aiden, and Hayden are the closest matches by sound. Most share Raiden's Japanese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"thunder and lightning"
"one who is learned"
"fallow land, uncultivated land"
"one who bails, deliverer"
"wise, wise storehouse"
"invented name, no established etymology"
"Yahweh is merciful"
"good fortune, luck"
"clearing among oaks"
"friendly, allies, friend"
"son of God's grace"
"son of Lawrence"
"beauty, grace, excellence"
"people's king"
"bowman, archer"
"famous warrior"
"divine power (from Oswald)"
"rock, stone"
"divine, god-like"
"graceful willow"
Similar sound: These names share phonetic patterns with Raiden — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Japanese origins, giving them the same cultural heritage as Raiden.
Rhythm: Raiden is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.