Sylvester Stallone is making his triumphant return to the cast of Expendables 4, but why did he leave the blockbuster franchise in the first place? After famously declining to return to the franchise he started and the $20 million dollar paycheck that came with it, Sylvester Stallone will return as Barney Ross to lead The Expendables mercenary team for a fourth time. In Expendables 4, the team is sent to Libya to stop a mercenary from stealing nuclear warheads. However, while the previous movies in the series were all about adding iconic action heroes with each consecutive release, the cast of Expendables 4 is stripped back.
https://screenrant.com/expendables-4-sylvester-stallone-quit-rejoin-reason/