Striker having a harmful effect, ignoring leader about Nationalist (9)
I believe the answer is:
lightning
But I can't explain it at all! Could you help me understand?
(Other definitions for lightning that I've seen before include "Natural discharge of electricity" , "Metal device on building for diverting natural electric discharges" , "Natural electrical discharge" , "Discharge of electricity in the atmosphere" , "Atmospheric electricity" .)