Shadergraph & Transparency Issues

Hey all, having some issues with Shadergraph.

Im trying to set up a 'Master Shader' for my game which needs to have the ability to change the opacity so i can fade out walls when i walk behind them. Ive got the Opacity wired up and when i slide the Opacity Node it does fade in and out. However when I have my normal map and albedo applied it looks like the croc below. Not quite sure what i'm doing wrong here? (Surface set to Transparent and Blend on Alpha, Two Sided is ticked off)

Thanks!