Transparency, as its name suggests, is a power that turns the user transparent, thus making him or her essentially invisible to the eyes of the opponent. The power, however, is merely becoming transparent, and is not complete teleportation at all. While being transparent, the user can only move at his normal speed, making it appear as teleportation and can be tracked by a superior sense of smell, such as Hawk's, and can also not bypass barriers, such as walls.
The latter weakness was exploited by Meliodas to defeat Golgius. Meliodas set a trap on the floor of the entrance of the room in which he, Elizabeth and Hawk were hiding in, since he, after realizing that Golgius' ability was not teleportation, understood that the Holy Knight would be forced to enter the room from the entrance and would fall for the trap.