Yeah but to be fair. It's not only Fairy Tail (and there was it only the last arc), it's a shounen thing. I have the feeling 90% of the shounens I have read are very against deaths lol. Only villains die in shounen. The heroes/protagonists survive. Or only a few characters are dying. In the last 10 years in the shounens I have read, there have maybe been only 5 or 6 characters who died. And that is a very small number. One Piece, Bleach, (Naruto), Boruto, Fairy Tail, MHC, BC, NNT, etc. are all the same. In my opinion.
So I can't see that William or Yami would die. Julius survives too. >__<
Not that I am sad about it, I am happy that he survived. But is's shows that the author or shounen jump itself are against deaths.
And to be honest, the devils could be summon without the death of one of them. And if William would die we never could see his true power. So it's a point more against there deaths. At least for me. ^^
BTW: Your Julius tag