An earlier interpretation has been corrected by a viewer: Athena (right) and the goddess Roma are attacking a giant. the character on the right is not Ares Ias I had earlier), because he is already represented independently in another scene. The most recent interpretations suggest the goddess Roma. This scene is a political message.
My source (Antalya sculptures of the Perge theatre gallery) had "Athena (right) and Ares are attacking a giant."