Tchernabog

Upon Casting this spell you consume 1 Twilight Essence, Upon Casting this spell as a standard action  you can enter a pocket dimension called " The Void " for 1 round  You will be the only creature in the void unless told different by the DM, 

you cannot return to the void unless you spend another Twilight Essence 

Upon reaching 7th level upon utilizing a full minute you can travel to somewhere you have been before 

Upon reaching 13th level You can stay within the void for 1 minute

Upon reaching 19th level you can stay in the void for 1 hour