i cant imagine a God of War game without Kratos. They could keep Kratos and have him go after other pantheons like Jupiter and friends, Roman mythology's equivalent of Zeus if i'm not mistaken. or maybe Baal etc etc
Or they can fast forward Kratos and have him take on the Viking's Gods the Asgardians
Or even fast forward to modern day and have him wreck havoc in modern times
kinda lame but hey, it could work.