By the Power of Grayskull!

Mattel Creations description:

Masters of the Universe and MEGA join forces to give you the power to build Castle Grayskull and give Prince Adam the Power. With this building set, you can recreate the iconic MOTU scene by turning the hidden wheel to “transform” Adam into He-Man, the most powerful man in the universe! Colors and decorations may vary.

• MEGA MOTU By the Power of Grayskull Building Set
• Build the backdrop of the Castle Grayskull façade
• Turn the hidden wheel to “transform” Adam into He-Man
• Adam and He-Man micro action figures with glow-in-the-dark Power Sword
• Comes in premium packaging with a glow-in-the-dark Power Sword design