Hi there, mohdmistry!
Nice work there! Great modeling and nice details. The anatomy looks okay too
Kratos is one of my favorite game characters. Nice WIP post as well, good overview of the progress.
Considering the displacement map, you might not need it at all. It depends on how you are going to use the character. If your character is for a game you don't want to use displacement maps, because the engine won't be able to render it in real time. For pre-rendered material such as cinematics and high detailed animation you might want to use displacement maps.
The silhouette of your character looks good though, so you will probably not need displacement on your character. Just do a dense retopo of your model and you should do fine with normal maps for applying the details of your sculpt onto your lowpoly model.
You probably knew a lot of this, and I might not be right, but that's what I have been told