The Walking Dead Season 6: 7 Things You Need To Know About Negan
4. All Out War
This is a major arc not just for Negan, but basically everyone still alive in The Walking Dead by the time it happens (starting in issues #115, while Negan first appears in #100). It's pretty much as it sounds, an all out war between Negan's Saviours and the other groups of survivors: Rick and Alexandria, the Hilltop Colony, and the Kingdom.
That should give you some idea of just how dangerous Negan and his group are: it takes three separate bands of survivors to team up just to try and stop him. It's bloody and brutal, full of twists and turns, and you're kept in suspense as to who will win until the end, although there are casualties on both sides.
If they introduce Negan then they pretty much have to introduce the other areas as well - which should hopefully mean saying hello to Paul Monroe and Ezekiel (and his tiger!) - and with that, you have the basis for the war. It'll take some time to set it up, but if they can successfully pull it off it would make for some incredible television.