I think there is a lot of material to continue Krato's story. In greek mythology after the titanomachy (the war between the titans and the gods) follows the gigantomachy, the war between the gods and the giants. Remember that in GOW AScension there is an enslaved giant in one of the levels. Besides storywise Kratos hasn't killed all of the gods,nor all titans, there are some of them left, like athena, apollo, artemis and aphrodite to name a few. Also Zeus could return like Athene did in a wraith-like state
There are also greek mithological heroes, most of them demigods, like achilles and bellerophon (he could be ultracool fighting alongside his Alpha chimera).
Also there are important members of Kratos family that still live. First there is Deimos, his brother, an ultrapowerful character that can handle himself against everything without upgrades nor magical weapons, currently he is dead but lets remember that kratos killed Hades, so Deimos probably escaped Hades as Kratos did so many times in the past. Also there is Cronos's Father, Uranus who is the primordial that started everything, and he is mentioned but unnnamed in Ascension's lore. He could return and form a new pantheon with the surviving gods, titans and giants, with him as their king. He could even posses Deimos as his new body, because Deimos is his descandant as is Kratos.
