Master Core

The Master Core is the final boss in the video game Super Smash Bros. for Nintendo 3DS & Wii U. It is the true form of Master Hand, and the player can only encounter this boss on Classic Mode on Intensity 5.1 or higher.

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 at least 5.1 difficulty, after the two Hands are dealt 70 HP worth of damage, Master Hand tears open to reveal the shadowy core inside covered by the Swarm called Master Core with Crazy Hand disappearing. The Master Core is a formless entity that attacks the opponent in various ways. It can take on many forms. If the player manages to deal enough damage to Master Core, the Core will revert back to its true form; as a ball. When in its Core form, the player has to KO it before it unleashes its one-hit KO Off Waves. Once the player knocks the Core itself into the blast line, Master Core is defeated.

Powers and Abilities
Each form of the Master Core has various abilities.

Master Giant
Master Giant is Master Core's most powerful form. This form can only be fought on Intensity 7.5 or higher. The Core takes the form of a large humanoid creature. It attacks by firing energy balls from its forehead and grabbing players with its hands or its forehead. Master Core is also capable of moving the stage vertically to try and get the player hit by its other attacks.

Master Beast
Master Core attacks the player by firing spikes out of the ground, chomp at them from the background with its large jaws, and do a full-body stomp that causes the stage to tilt for a few seconds. It also generates electrical discharges as well. This form can be encountered on Intensity 6.0 to 7.4, or when Master Giant is defeated.

Master Edges/Sabres
Master Core takes the form of multiple swords. The swords can attack with either homing attacks, or perform slashing attacks. They can even generate energy slashes that can be absorbed (by Ness and Lucas). This form can be encountered on Intensity 5.1 to 5.9, or when Master Beast is defeated.

Master Shadow
Master Core takes the form of a shadowy form of its opponent. It is slightly bigger than its opponent, and its attacks are slightly stronger. However, as the Core takes damage, it gets smaller and smaller. This, form appears after Master Edges is defeated.

Master Fortress
Master Fortress is a form that's available only in the Wii U version of the game. In this form, Master Core takes the appearance of a huge fortress with enemies and orbs to hit to make new paths. When the Fortress appears, the player receives a heart to replenish their health, and timer is reset. In order to defeat this form, the player(s) must destroy all the cores within five minutes. It's very similar to the Smash Run on the 3DS version and Race to the Finish from pre-Brawl. The form is its most powerful incarnation in the game and appears on intensity 8.1 - 9.0 after the Master Shadow.

Master Core
The Master Core at its weakest. It becomes vulnerable and stationary at the center of Final Destination, unable to attack its opponent. When the player attacks the Core, it won't retaliate. More attacks to the Core increase its damage percentage for easier knockout. However, if the player doesn't KO the Core within a certain amount of time, it will unleash a one-hit KO attack, similar towards Tabuu's Off-Wave attack. If the player has an extra life, the Core will continue the move about five more times until it self-destructs. Fortunately, much like Tabuu's Off-Wave, if the player performs either rolling dodge, or the sidestep dodge at the right time, then the player can survive the attacks. This form appears after either Master Shadow or Master Fortress is defeated.

Trivia

 * During the battle the background music will occasionally go silent and a few quick beeps will play. Those beeps are actually Morse code and spells out "Master Core".