If Could Use Only One Indicator For E-Mini Trading, What Would It Be?

In my e-mini trading I like to isolate and measure multiple variables to look for convergence in those variables. Of course, I recommend drawing trend lines and support/ resistance manually, which is my current practice, and I use Better Renko bars to display price, range, open and close. In some respects, this is all you really need. On the other hand, a little help in analyzing price would be helpful.