Here’s the classic ‘shimmer’ reverb in VCV Rack.
It’s basically reverb with a pitch shifter in a feedback loop.
I’ve used Clouds to provide a two octave shift, and the mixer returns some of the output back to the input of Plataeu to make the feedback loop. It’s set up to use as an insert effect with the VST version of VCV, if you want to run it in standalone mode, just patch the sound you want affected into the Mix4.

You will need the following free module collections:

Nysthi
Bogaudio
Valley
Audible Instruments