The Soul Surge takes the form of Excalibur slicing across in a circular motion, both as an icon and on the tracks.
In gameplay, the Soul Surge can only be obtained at random from Item Boxes by Excalibur Sonic. As with most other Items, Metal Sonic can also use the Soul Surge if he uses the Steal Item to steal it from the aforementioned user.
Once obtained, the player can utilize the Soul Surge by pressing its icon on the bottom of the HUD. In addition, when obtaining the Soul Surge, there is a chance of obtaining up to two Soul Surges to use in the Projectile Item slot on the HUD from a single Item Box. When used, the user performs a horizontal sword slash around themselves that can damage rival characters adjacent to them, in front of them, or behind them, causing them to lose Rings and slow down momentarily. To avoid the Soul Surge's slashing attack, the playable character either has to jump when Excalibur is about to hit them or get to a lane that the attack cannot reach.
The Soul Surge can also be upgraded by leveling the user up to level 6 and 12 respectively. For each upgrade, the player will increase the chances of getting two Soul Surges from a single Item Box.
- The description for the Soul Surge contains one of the quotes spoken by Excalibur during the battle with the Dark Queen in Sonic and the Black Knight.