Drive 8 leds with On/Off and PWM using 8 pots and 1 pwm
If you have a micro controller driving 8 LEDs you would normally not need any extra components. (The exception would be if your controller is so busy that it does not have spare cycles to control the LEDs. But then you probably have chosen the wrong controller).

You can make a PWM in software and got through a loop too drive the pins one after the other. Because the eye is slow  a PWM at e.g. 100 Hz would suffice. (But I would try to go for  even higher e.g. 200 Hz).