beautiful jade, star
琁 centers on something precious and radiant: a beautiful jade gem, and by extension a star, which shines like a jewel in the sky.
琁 combines 王 (jade) with 疋, which likely contributes a phonetic element. The exact historical development of the right side is uncertain.
The left side 王 is jade, and the right side 疋 looks like a foot stepping forward. Imagine a beautiful jade stone so radiant it leaves a trail of starlight with every step.
For セン, picture a beautiful jade star sending out rays of light: send -> セン, as the star sends its glow across the sky.