Thread:EvilDragonLord/@comment-33959269-20191115232304/@comment-5494183-20191116040150

As you said, the Commandments were half of his power, so that wouldn't mean necessarily that he would die if these are destroyed.

The Demon King that was fought, was not his actual physical body, as he manifested himself in the real world through a medium (Meliodas, Zeldris, etc.) with the help of the Commandments. With their destruction, the DK could not return to the real world. We could interpret this as what Merlin or Meliodas said about destroying the DK, maybe implying that his body would be now trapped forever in Purgatory, so they wouldn't have to worry about him anymore.

In any case, as there is room for some ambiguity, it was opt to leave it as "Unknown" for now.