User blog comment:IamJakuhoRaikoben/Chapter 389: The Twin Dragons vs. The King of Hades, Review./@comment-24467372-20140620101344

Mard didn't even move from his spot against all that...He isn't even trying >_>

I'm sensing he will pull a Gildarts style Reiatsu crush against the twins after they hit him with their best abilities. They'll think they have won but when the mist and the rubble clears,Mard will come out smirking once more.

And then he'll stomp them...

Was I the only one who noticed the Dragon Slayer remark by Mard??

Is there any other form who can use DS magic other than humans??

Very interesting....

It's either referring to Natsu(Who somehow will turn out to be E.N.D)

Or it's actually hinting something that most of us figured out only. Acnologia being a hybrid dragon...

I think Acnologia was a semi-demon(Like Mard and the other 9DG) who had DS powers... And when he became a dragon,he kept that. He is a Dragon/Demon hybrid. That's why he is so far above the other dragons and has "pitch-black" wings(Something that Arcadios included in his explanation to make a point)...