A distance field-based fade material
Create a dissolving effect that's both believable and easy to control
Use distance field and height lerp to blend the edge
Making the dissolve mask with a noise map
Randomness trick called Cell Bombing
The mask above would shatter the mask into small pieces
...and recombine them like this
Use DistanceToNearestSurface to define the "Fading" part and the "Visible" part
Separate two parts with different colors
Now we can see the blending area already
Adding More Masks
Adding Height input preparing for height-lerping
Adding a solid edge to make it extra shinier, as well as a scalar to allow the fading part to extend
Another mask to add a bit more randomness to the edge
Blending Method and Outputs
Now we've got this function that could be applied to any opaque material, just switch the blend mode to Masked and it'll work!
Make sure the target mesh doesn't affect distance field lighting, and insert another mesh into it
If you wish to hide the block, be sure to turn "Affect Indirect Lighting While Hidden" on