The term 'controlling influence' can be summarized by two crossword solutions: REINS (5 letters) and SWAY (4 letters). REINS refers to the straps or lines used to control a horse, while SWAY is defined as the power or influence that someone has over others. Both terms are used to describe the power or authority that someone has over a situation or group of people. In this context, controlling influence is the ability to direct or guide the actions of others.