User blog comment:IamJakuhoRaikoben/Chapter 473: Red Lightning, Review./@comment-86.66.207.93-20160215171847/@comment-86.66.207.93-20160215173248

for the red lightning i also found the explanation with this article : https://en.wikipedia.org/wiki/Sprite_%28lightning%29

So it seems Laxus changed the polarity of his lightning and mixed with other elements ( probably in the air ) to create something new, the term mercury fulminate is used to describe it : something that explodes on contact with the target