Master Core (Super Smash Brothers 4)

The Master Core is the true antagonist in the video game Super Smash Bros. for the Nintendo 3DS (it's currently unknown if will stay as the final boss for the Wii U version). It is the combined form of the Master Hand, and the Crazy Hand and the player can only encounter this boss on a certain difficulty.

History
When the player is playing Classic Mode and managed to reach the Final Destination, on a certain difficulty, they can choose to confront both Master Hand and Crazy Hand at the same time. On a certain difficulty, after the two Hands are dealt with a certain amount of damage, both Master Hand and Crazy Hand merge together to form the Master Core. The Master Core is a formless entity that attacks the opponent in various ways. It can take on the forms of a Sapien, a Scorpion, five Sabres and even a more powerful clone of the Core's opponent. If the player manages to deal enough damage to the Master Core, The Core will revert back to it's true form; The Source. When it's in it's Source form, the player has to destroy it before it unleashed a one-hit KO move. Once the player deals enough damage to the Source, the Master Core is defeated.