Where does “煞” come from?

煞 (Chinese) comes from Chinese 殺, from Proto-Sino-Tibetan *g/b-sat.

Ancestry of “煞”, step by step

Step	Language	Word	Meaning
1	Chinese	殺	—
2	Proto-Sino-Tibetan	*g/b-sat	—

煞 — Etymology, Origin & Word History | Etymology Explorer