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"
"record keeper"
"rowan tree (mountain ash)"
"meadow land"
"to tame, to subdue"
"God is my judge (variant of Daniel)"
"trustworthy, loyal"
"pure, innocent, righteous"
"bold warrior"
"where roses grow"
"God is gracious (via John → Jack)"
"born of fire"
"always king"
"Poecc's estate; Poecc's settlement"
"appointed, placed by God"
"selected, set apart, elected"
"wise protector"
"little saint"
"descendant of the dark one"
"narrow strait, channel"
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.