Draugr's War

I don't need a shield, I'm immune to the blade
I'm the price of the debt that you never have paid
Falling through history, dust on the cape
Once I have started, there is no escape
My voice is a tectonic shift in the floor
I'm a beast, I'm a titan, I'm something much more
I've seen all the empires crumble to sand
While I kept my grip on the sword in my hand