Going back to the year 1997, Kane made his debut as Undertakers little brother, and immediately shook the WWE. He was first established as a big star by the fans when he burst through the hell in a cell match with his brother and Shawn Michaels and tombstoned Undertaker.
For years after, He was known as The big red machine and partnered with Taker as 'Brothers of destuction'. He was mysterious as he wore a mask, and told the fans he had been burnt as a child. Kane repeatedly turned on his brother through the years, and always destroyed his opponents.
In 1998 at Unforgiven, Undertaker beat kane in an inferno match, Burning his arm. In 1998, Kane defeated Steve austin to capture the WWF title for the first time in his carrer. He then won Intercontinental titles and Tag titles over the next few years.
In 2003 on an edition of Raw, Kane lost a match to Triple H and was forced to unmask himself. Within doing so, WWE unleashed the real monster inside of him and therefor Kane got extremely angry.
At survivor series 2003, Kane helped Vince McMahon to bury the Undertaker alive. He then lost to Taker at WrestleMania 20 and started to die down a little as a monster after that. Kane won the Tag titles with Big show in 2005 and became a good guy.
Coming into 2006, Kane put on a bit of weight and was liked by the fans. He wasn't a champion from mid 2006 - this WrestleMania and was just an average superstar.
Throughout 2007, Kane was a Smackdown superstar and didn't win a single title. At WrestleMania 24, Kane won the ECW title from Chavo and was still a good guy. He then got drafted to Raw in June of this year and brought out this little burlap bag. Everyone was expecting Kane to bring back his old mask, but it turned out that it was infact Rey Mysterios mask in his bag. He told the fans that that he had destroyed Mysterio beyond human recognition.
From this, Kane brought back his evilness, and therefor brought back his old terrifying theme tune. By the looks of it, Kane is BACK !! and is evil again.