This is just an idea that came to mind just now, but, the main topic of this thread is to talk about superstars nearing the end of their careers being able to elevate the next generation. I chose the Undertaker...
The Ministry of Darkness hasn't been seen or mentioned in the WWE for over 10 years, and I think now would be a good time to bring that faction back. As much as I hate the guy, he's really the only one credible enough to have a believable feud with The Undertaker (besides Kane), but John Cena. I would book Cena in a feud with Taker after Brock, for WM29. I would have The Undertaker play the heel role, even though the fans would easily turn that around most likely. And, leading up to Wrestlemania, I would have John Cena feud with superstars of his choosing. Which would all make up his new ministry. First, I would bring Reks and Hawkins up to the main roster with a dark/grunge gimmick and start them out as a jobber tag team, to elevate the other jobber teams from "jobber status"... (that will make since shortly)... I would have The Undertaker bring back a dark, evil, heel Christian. "Brood Christian", if you will, to feud with Cena. After that feud, I would put Christian with Hawkins and Reks for the new Brood. There's your first 3 members of The Ministry. After that, possibly try and bring back Viscera to add to the mix to feud with Cena as well.
Now, here's the kicker. Other than Kane, nobody else really has "powers". So, after those two are gone, there will be absolutely zero character left in the WWE, and everyone will be the same. So, I would go to FCW, and find a big guy, bring him up as The Undertakers son. He inherits the evil, the power, and after Taker is retired, you'll still have that evil character to fill the void. I would have him feud with Cena until the Rumble, and at Mania, help Taker beat Cena. Only to turn on his own Father. Then, Wrestlemania 30, have The Undertakers son somehow retire The Undertaker. So, out of that, you get a brand new character, new tag team, and hopefully Christian as a solid main eventer.
Toughts and ideas are appreciated!