When you mention the name of the Baba Yaga, John Wick, Keanu Reeves instantly comes to mind, but that wasn't always the case. During the creation of the first film in the franchise, when the first script was put onto the plate of producer David Leitch, who at the time was also regarded as the co-director of the movie alongside Chad Stahelski, Bruce Willis was attached to the project.
As confirmed in an interview with Leitch with The Hollywood Reporter, it's specifically noted: "We were first exposed to the script by our manager at the time, Kelly McCormick, who's now my wife and producer. She had introduced us to Basil Iwanyk and Peter Lawson at Basil's company [Thunder Road] to maybe do second unit work on that script. So that was the first time we read it, and I think Bruce Willis might've been attached at that time."
This clearly fell apart pretty soon and led to Reeves taking the lead role in the franchise. It is unclear how long Willis was attached to the film before Reeves came onto the scene, but in hindsight it's probably a good thing that Reeves did come along as his signature gruff tone, appearance, and swagger was probably not something the Die Hard actor could replicate.