“I came across this at a very sad point in my life, it was on a hard drive on a vintage computer I bought off Amazon,” Marshall explains on the expansion’s GitHub page. “Literally this essentially saved my life, I was going through a divorce and just happen[ing] to come across something like this was insane.”
Death of the Outsider is the game after 2. It’s technically a stand-alone expansion rather than a game, though; it’s more like Dishonored 1’s Knife of Dunwall and Brigmore Witches expansions than it is a proper Dishonored 3, it just runs on its own executable rather than from a menu within Dishonored 2.