You could put the wire in the vulnerable area - perhaps using the same drone? But I don't think it would be any use. A lightning strike releases about 1 GJ of energy, mostly into the sky. So the effect at the target would probably be no more than a few kg of explosives which you could have delivered using the wire anyway.

Plausible deniability?

People tend to get mad when you bomb them, but if no one noticed the drone in the storm it's just a natural strike...

Fire it at a transformer, take out power in an entire region and blame God. A perfect tool for the CIA.

A sniper rifle does the same, with a single shot, more reliably and without witnesses.

But it leaves pretty clear evidence of human action, which CIA-style actors may not want.