RTF is a global modification that replaces all towns in the game.

The upgrade could create an explosive ballista or an iron ballista, like in NCF, but with a color scheme resembling the dwarven ballista from Heroes 7. Alternatively, it could be better to create a ballista with a gun crew, inspired by the dark dwarves, instead of a regular ballista. Alternatively, a dark cannon could be used, or even a fire or electric cannon.