User blog comment:CNBA3/Chapter 405 Review/@comment-4829046-20141020120040/@comment-5303512-20141020121055

Natsu is just care free ... And yes stupid as well. To stupid in fact to insult.

The only reason I say this theory is because I have been curious as to why Mard can use Telepathy similar to Warrens and that he seems the most human of the Demons.

My prediction is that as the former Dragon Slayer just like Natsu and the Others, Acnologia abandoned him but then E.N.D. came along and tempted him to becoming the "Demon King" thus ending his life as a Dragon Slayer,