Using the Gray Quake, the user transforms into a gray iron ball with yellow eyes. In Sonic's case, his entire body turns into a gray rhombicuboctahedron which only shows his eyes, albeit without pupils and colored pale yellow, which take up two squares on the surface and are connected by a small string.
Powers and abilities
As the Gray Quake, the user's body density is greatly increased, making them so heavy that jumping or falling down on the ground can create destructive shockwaves across the area, powerful enough to tear apart robots and break down the environment. The Gray Quake also possesses wallcrawling abilities, allowing the user to scale walls despite their weight in this form.
The main drawback of the Gray Quake is that it makes it harder for the user to move around. Additionally, it can only be used for a few seconds and requires more Hyper-go-on from Gray Wisps to be maintained.
In the 3DS version, the Gray Quake is first used in Silent Forest Zone 1. In gameplay, the player can only use the Gray Quake while in possession of a Gray Wisp. Transforming into the Gray Quake will cause the Wisp Gauge to start depleting, and once it runs out, the user will revert back to normal. To extend its duration, the player has to collect more Gray Wisps. The player can also touch the Sonic icon on the touchscreen to transform back to normal, though at the cost of losing the Gray Quake.
The player can transform into the Gray Quake by tapping the icon of the Gray Wisp on the touchscreen. As the Gray Quake, the player moves forward automatically and can both plow through gray-checkered walls and damage enemies upon touch, though the user can still take damage from things such as iron balls. To move left and right, the player has to tilt the Nintendo 3DS to change direction. The player can also press / to jump and / during a jump to slam into the ground which will damage all surrounding enemies and obstacles. Additionally, the player can climb straight up walls by running into them.
In the Wii U version, it is used in the VS Mode, which stuns the opponent for a few seconds when used.