User blog comment:FairyRaven/Fairy Tail Chapter 404: 00:00, Review and Commentary/@comment-1776824-20141011135516/@comment-25111584-20141011141014

Magna Carta was forced on the King by the barons, giving them greater powers ...

I still stick to my theory that Mard has his own agenda which he did not reveal to the NDG. So I think he'll somehow try to usurp E.N.D.'s place and control him, which is what the barons did using Magna Carta. He might use the power of Face to do this rather than because it is required to revive E.N.D. ...

Would also explain why he kept Silver as a deterrent, after all, Silver was never a threat on his own ...