This is a cake that will haunt me. I redid the darker gray fondant, 3 times. There is so much wrong with this cake, I don’t know where to begin to start.
All of the faces (sides) of this cube should look identical to the top side of the cube.

If you ever have to do a cake similar to this, there are many instructions on the internet. One mentioned that they formed the corner pieces over a 6" square cake pan which would eliminate the seams on the corners.

I failed to measure the corner pieces correctly. I placed the top pieces on first, which let me hardly any wiggle room on the base of the cake. I should have started from the bottom and worked up in this instance. It would have allowed me more room for adjustments.

I did my best and it wasn’t good enough. Next time, I will try even harder.
I actually gave this cake to the young man who ordered this for his wife on their second wedding anniversary.
I didn’t have the heart to charge him for my mistakes.