Chitty Chitty Wang Bang
I came back into Shadow Warrior last night, and I got past chapter 10 and ran into the next demon boss in the 11th chapter: Mezu.
He is one of the immortal demon beings ruling over the Shadow Realm known as the Ancients, now he became a more powerful demon than ever. So now I just need to look up some instructions online on how to defeat Mezu so I can move on to Chapter 12.