Well, there seems to always be plenty opinion on these two guys, two guys easily considered as legends, and two guys who like it or not are nearing the end of the road in the WWE as active Wrestlers, there also always seems to be opinions on how they will leave the WWE and when it will happen.
Here is my two bobs worth on how the WWE could play it out.
Firstly, I don't think either will retire at any WreslteMania, mainly the Undertaker, as I feel with his character, he will finally 'Rest In Peace' and I don't think he can do that with a win, I think when he goes he will need to be killed off for good and I don't see him losing his WrestleMania streak, so for me, it would be the place that started it all off, Survivor Series!
Kane and The Undertaker would be quite close they'd need each other, however, as time goes on Kane somehow always seems to be the one on the receiving end of the beatings, he is the guy who would be receiving the punishment, while The Undertaker would get the wins, and with it get the adulation of the fans, Kane would become more and more erratic, he would start intentionally letting The Undertaker take the beatings and wouldn't be quick to help him out, as time goes on and Kane becoming more and more unhinged, The Undertaker would confront him on his behaviour, Kane would back off until The Undertaker had turned around then he would attack him before Tombstoning him and leaving him in lying prone in the middle of the ring.
Over the coming weeks The Undertaker tells Kane that he isn't mad and what happened happened, he isn't interested in getting into yet another feud with Kane, Kane however would become more and more unhinged as the weeks go on, he would come out and spoil matches, attack refs, backstage workers, commentators, he would be constantly out of control, he starts going on about Paul Bearer, he was the only person who could control him, he needs Bearer, Taker tells him Paul is 'unreachable' and Kane again turns on him saying its his fault he is unreachable since he buried him in cement.
The Undertaker would go on to tell him that Kane should know what he did, he did for the best and he did it for Kane as well as himself, Kane however can't accept this, he is regressing at a fast rate but also an erratic rate, Kane would come out one week with the mask but only the trousers on, he would then come out with the full outfit but no ask, he would have the mask without the wig and he would wear the mask with the wig as well as the outfit, as time goes on his reign of terror becomes more and more ferocious, holding Diva's hostage and certain people on the roster just disappearing altogether, fire would engulf the ring on certain occasions and Kane's presence would always be felt, all the while The Undertaker is constantly trying to regain control of Kane, trying to keep all who want revenge on him at bay.
The Undertaker would finally have enough, after going through THREE guys on one night who want revenge on Kane, Kane makes yet another appearance and after destroying the last of The Undertakers opponents he would then once again turn on The Undertaker, the next week on SmackDown! there would be a Superstar revolt where all who has suffered at the hands of Kane would become vigilantes in their quest to find and punish Kane.
Vince McMahon who was the latest victim of Kane's mental torture told Kane that unlike the rest he has the power to make every single breathing moment of Kane's existance hell until his dying day, he is going to torture him when he and the rest of the vigilantes get him, this brings out The Undertaker, he tells them to back off, then tells him he will deal with Kane, if any of the vigilantes have a problem with that they're told to speak up, no one does, The Undertaker tells them all he knows how to end this now, its time to bury the bad feeling, bury the hatred and bury the anger, he is going to face Kane at the Survivor Series in a buried alive match, when Kane is buried he will "REST IN PEACE" forever!
Before the match The Undertaker finishes his promo saying "Only the Darkness can protect you however the Darkness will need to accompany you into the beyond"
At the Survivor Series as the match is nearing its close, Kane drags The Undertaker to the grave, Taker would come around and hit Kane with a Tombstone, he would nail him with a further two completely annihilating Kane, he drags Kane up to the grave and dumps him in the empty Grave yard, the grave diggers are about to fill in the hole when The Undertaker stops them, he looks up to the crowd one last time and signals the "throat-cut" sign, he then launches himself into the grave with his brother Kane, thus "protecting him" by killing him but also going with him "to accompany him into the beyond"
With that the bell tolls as the Undertakers music fills the arena one last time
