Quote Originally Posted by Alberel View Post
Just to expand on this a little:

Ilberd very specifically says he will "become a demon" which implies he either intends to become a primal as Louisoix became Phoenix, or he plans to act as host to a primal as Ysayle and Thordan did. In either case there is heavy implication that Ilberd is not entirely dead. This may explain the two human feet we can see within the closing Dalamud.
One thing I'd like to mention: My own interpretation of that line was that while Ilberd may have betrayed us he is completely aware that Primals aren't good things. But if summoning a Primal helps liberate Ala Mhigo he will sell his souls to the darkest devils to do so.