Demo of the Dusky Electronics Mandorla
https://duskyamp.com/models/916A/
My take:
This is a classic MOSFET treble booster design. I found that along with boosting treble and volume, it also cut the mids a bit. Treble boosters are very interesting to me – they can really shape the color / overall vibe of your tone. When playing the Mandorla, I realized it was making me play differently – it was accentuating the high treble-y frequencies and that made me want to hit them more often. Useful pedal! Check it out.