How to deobfuscate JavaScript

Hacky code used in the reverse engineering streams here : https://www.youtube.com/watch?v=xkoFgPEfFLk&list=PLoZcQiQmH1DX6BEZdTJ6DifssHt9A8zaH

No guarantees as to the state of code here. This will all be cleaned up at a later date.

• Stage 1 https://www.youtube.com/watch?v=xkoFgPEfFLk
• Stage 2 https://www.youtube.com/watch?v=YqmmFXVAEkA
• Stage 3 https://www.youtube.com/watch?v=5eXpC6rx06U
• Stage 4 https://www.youtube.com/watch?v=BdfHCOCL8fc
• Stage 5 https://www.youtube.com/watch?v=VxgEwi6LfLc