When two VERY differant worlds collide

All seems normal in Equestria at first until Princess Celestia is informed by the royal guards of a strange portal in the castle gardens and she informs the Mane Six of the portal and requests them and Twilight Sparkle's Brother, Shining Armor, to see what is beyond the strange portal... and what they find beyond the portal.. will Horrify and scar them for life [CURRENTLY ON HOLD]