Talk:Sunset Shimmer/@comment-24659719-20160219034033/@comment-24659719-20160220012659

princess twilight uses celestia's book to open the portal from equestria. when she returned home from the human world she would have removed the book from where she placed it on the construction she made, thus closing the portal off. since it was used as a power source to open the portal. i believe that the portal acts like a stargate, it needs a big enough source of power to open it to send someone through, the state that it is in normally is capable of sending messages through, but not a person or pony. as it would be irresponsible to leave the portal fully open all the time. in rainbow rocks i believe the other girls were guarding the portal like they were in through the mirror, however it was spike who was guarding it when twilight came through in friendship games.