That's a basic chorus. Repeating "God of War" for catchiness. Mentioning Aesir and Vanir, which are groups in Norse mythology. Using "blood and thunder," which is a nod to the first game's Colossus.
Also, check if there are any specific elements from the game that are iconic. The transformation into the God of War with the Leviathan Axe. The game also has a lot of blood and thunder, which is a reference from the first God of War with the Blood and Thunder colossus. Maybe include that. Maybe some references to Kratos becoming the new Odin. The story of God of War Ascension is about Kratos coming to Asgard, seeking revenge on the Aesir gods for his past. god of war ascension rap file
[Outro] might wrap up his legacy, like: