I would suggest looking at the waveforms generated by Massive. Focus on Bender.
Grab the audio samples from here:
The Sine Shaper: you may have to fiddle around with Distortion along with Key Trig/LFO Envelopes on some of the parameters.
Example how Sine Shaper works.:
As for randomize samples:
The key to understanding how the waveshape is achieved is to follow that video and figure out what are the Renoise equivalents parameters to achieve what the person is doing.
