The Resonator Bank is a very versatile device. In this video, I show three small application areas. Basically, you can add harmonies to everything that was atonal before.
Whenever I create pads I use the Bitwig "Resonator Bank" at least once to turn atonal sounds into tonal ones. That you can create melodies with the keytrack button is an important feature and also that you can influence the resonator from other tracks with notes makes it a versatile instrument.