We recently learned that the Super Saiyan 4 form will make an appearance in Dragon Ball FighterZ as part of a secret Meteor Attack by Goku (GT). We got a first look and some updated info in the latest issue of Jump magazine. [Thanks, @Spytrue.]
The Meteor Attack by Goku (GT) is described as the most powerful Meteor Attack that comes with a special scene that you can watch when the right requirements are met. The magazine also shows info stating that you can perform the SSJ4 transformation when even a single ally from your team falls, not two. This Meteor Attack, “Dragon Fist,” is shown on the scan with Goku hitting the opponent with the golden dragon.
The move is used after launching opponents in the air to follow with a reverse Kamehameha and a powerful dash attack.
Dragon Ball FighterZ is available on PlayStation 4, Xbox One, Nintendo Switch, and PC. The Goku (GT) DLC is expected to release in May 2019.