This is the 7193rd most frequent Japanese word.
一輝
"一輝" (Ikki) is a Japanese male given name meaning "one radiance" or "one brilliance."
In this context, 一輝 (Ikki) is used as a proper noun, specifically a person's given name.
一輝さんは医者です。
Mr. Ikki is a doctor.
Here, 一輝 (ikki) is used metaphorically, meaning a 'moment of brilliance' or 'one radiance'.
彼の一輝に光が射しました。
Light shined on his moment of brilliance.
In this example, 一輝 (Ikki) is again a proper noun, representing a person who is the subject of the journey.