The Punisher Villain Jigsaw Explained

Netflix's The Punisher: Season 1 wrapped up with the badly disfigured Billy Russo -- ex-friend of Frank Castle -- clinging to life in a hospital bed and silently vowing revenge against Castle, locking him in as the villain Jigsaw in Season 2.
And now with Season 2 of the Netflix show debuting, here's everything you need to know about Jigsaw and why he's managed to stay the one recurring thorn in the Punisher's side all these years.
Jigsaw Explained: The Basics
Given that the Punisher's entire mo