My other two Chaos armies are Death Guard and Emperor's Children. Originally I had pieces that I had bought for these two armies, which once the new Codex was realeased I found that they could not have. So I decided to paint them anyway as a different Chaos Chapter. I liked the idea of having a Wordbearer army, as it fit in with the background I am doing for Chaos Imperial Guard, and because I can use the demons from my other armies as troop choices I figured I could build this one the fastest.
So now all the pieces that were left out from my other armies now have a home in the Wordbearers Legion, and I shall use all my daemons from my other chaos armies as my troop choices.