Sakurai’s latest Smash Bros screenshot is quite the doozy. No less than Samus Aran’s 1st nemesis, Mother Brain, reappears as a gigantic Assist Trophy.
An Assist Trophy is a special item that summons a given Nintendo character to immediately aid the holder. The assist activates as long as the character holding it is standing on the ground, and is not jumping, on hitstun, or in any other status.
Mother Brain is as grandiose an Assist Trophy as you can get. She is actually an AI created by the Chozo. She was intended to help bring order to the universe, but turned on the Chozo and sided with the Space Pirates when Ridley invaded Zebes. She appears as the main villain of Metroid, Super Metroid, and Metroid: Zero Mission.
In the screenshot, she is shown connected to her tank, called the Control Capsule in the Super Metroid comic. The Capsule has presumably been broken after Samus’ attacks, which means she is an even more lethal opponent to deal with. As described, she is protected by Rinkas, energy rings that regenerate constantly around her. She also throws an eye laser brain attack to Samus, one of her most lethal attacks in the original Metroid games.
As Sakurai has demonstrated before, he is deliberately changing things up for Smash Brothers for Wii U and for 3DS where he can, and making choices to make the game more competitive. Between Mother Brian, Skull Kid, and various other quirks, we see that he is making a more aggressive Smash for 8th gen as well.