Actually, the entire post is about its theme, leading up to a conclusion about its name. Here: "With things like Valkyrie, Raiju and Buraq this seems more like an Element of divinity and mythos. 'Course, divinity is in Light and mythos is everywhere."
Thunder was picked out of Electric and Thunder because of the reasons I mentioned and because the OP presented those two options. That's all there is to that.
