This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 刢 is uncertain. It combines 令 and 刂, but the original semantic and phonetic roles are unclear.
With no clear meaning, picture the components: 令 (order) and 刂 (knife). Imagine a knife cutting an order into pieces, but the result is uncertain.
For レイ, imagine a ray of light (レイ) shining on the knife 刂 as it cuts through the order 令: ray -> レイ.