User blog comment:Iam69god/Why is "Lost magic" lost?/@comment-27281341-20160908192005

It's because Lost magic is magic that can seriously mess up the world, so in the end people stopped using it. It's a subcategory of ancient magic. Also, many of it's types affect negatively the user in some ways. They have repercussions. There are a few examples of this happening in the sries, but i won't spoil them.