This UI uses custom textures.
Download them from this OneDrive link. (I might eventually find a better way to host these.)
Unzip inside .../Interface/ next to .../Interface/AddOns/, such that you have .../Interface/CustomUI/icons/ etc. The .zip file includes other resources I use in my weakauras; the ones you don't want can be deleted (e.g. /CustomUI/sound/). They're included since the entire folder is small. Feel free to repurpose them!
Remember to restart the game--not just log off--for these to show up.
An overlay indicator for Ineffable Truth procs. The overlay is separate from the rest of the corruption buffs (link here and also found in the collection for these UI weakauras), to allow for repositioning the corruption HUD separately.