Proof of God of War 4 and My Theory?

So,God of War 3 is the end of the series eh? I think not. When you beat the first game on Hard mode, a video is unlocked talking about the brother of Kratos. It reveals that Kratos was chosen over his brother to aid the gods. His brother was sent to the mountains to fend for himself, and he soon died and went to Hades. It claims his brother swore revenge against Kratos. So my theory is that the next game you are either Kratos' brother after Kratos, or Kratos after his brother. Another theory is after you beat the game on Very Hard or God mode, a video is unlocked showing a modern day swat team arriving in helicopters and hummers at the dead corpse of Kronos. It then say "Like in all great myths, a new hero is born." Maybe a descendent of Kratos. So what do you think? And do you have any theories?