Lightning goes down to the ground through the route that offer the least electrical resistance. It is that simple, but really not that simple when you look at the details.
Sometimes you see ligthtning up there going sideways to another spot in the air, apparently getting not the least bit closer to the ground, that we miss in that scenarion is ionized air. a patch of ionised air is a good conductor, so if there is a bit of voltage difference between where the lightning originate and some other place up in the air, the lightning may use such an ionized patch of air to get there. That gets it a little closer. but there may still be too much resistance between the lightning and the ground for the lightning to go Crraak and strike down to the ground.
Anyway a unicorns horn (better know as a Narhvale tooth) is a lousy conductor (even worse than normal air) so it wont make a good lightning rod. Pretty cool theory, but off the mark :-))
This post was edited by JakobA the unAmerican. at October 18, 2017 8:43 AM MDT