Transformers Generations Sky Shadow is a recoloured, remolded, version
of Transformers Generations Thunderwing based on the original Japanese
Black Shadow toy from the Transformers Victory line. Back then Black
Shadow and Blue Bacchus made up the group known as the Crossformers. In
2011 the name Black Shadow could not be used, so Hasbro went for
Skyshadow, a name with several uses previously in the line.
The original Black Shadow toy is quiet hard to find, though you can see a
full image gallery of that figure on Transformers At The Moon. This
image gallery of his Transformers Generations update also features
comparison pictures to the original.
Transformers Generations Skyshadow is a really nice toy and a great
partial remold. The figure took a while for release, but the colour and
molding changes make the toy significently different from the original
Thunderwing release.