Elite Four are a group of tough Trainers.They are tougher than all Gym Leaders in that region.There are four of them.Each one is tougher than the last,with the exception of Unova.You need 8 Gym Badges to battle them,and after you defeat all four,you go against the Champion,except in Unova(But the second time you battle them you do).They each have a specified type,most of Them are:Psychic-Type,Dark-Type,Fighting-Type,Ghost-Type,and Dragon-Type.One of the most unusual type line up of the elite four is Sinnoh's,with the exception of Lucian