Is there something like Logic’s Drummer in Cubase where you can adjust a drum loop complexity etc?
There’s nothing else quite like Logic’s Drummer. Apple really did a nice job with that. However, there are some good plugins for adjusting things like complexity in a groove. Stylus RMX is indispensable when working with loops. It allows you to adjust many things about the feel, including the complexity. EZDrummer allows you to adjust the complexity of midi drum grooves. And Groove Agent of course. Jamstix has some nice features for following you and improvising like Logic’s Drummer.