Thank you for sharing Alex Mathias. What an inspiration!
For anyone that still needs it:
1. Create a section
2. Section > Style > Background > Gradient > Location 50 / 50 > Linear > Angle – 45
3. Section > Advanced > CSS Class > test (whatever class name you want to put)
4. Section > Advanced > Custom CSS
background-attachment: fixed !important;
background-position: center !important;
background-repeat: no-repeat !important;
background-size: cover !important;
5. Insert Heading Widget > Style > Blend Mode > Overlay
6. Heading > Style > Blend Mode > Difference
That should be it. Good luck!