Older and Wiser

This character was one of the original protagonists. They hung out, had adventures, and had the Grand Finale with the rest of the cast once the show was cancelled. Now the show has had a Revival, and the character's back, with a twist -- they're a generation older than the new cast, and they've come back specifically to help the people who are in the same situation they once faced. This role can also be filled, in a Long Runner, by a character who leaves and comes back after a significant span of time.

Related to The Obi-Wan, though they're less likely to die. (Of course, there's always the possibility of a nasty refrigerator accident...)

Anime and Manga

 * In Gate Keepers 21, several of the heroes from the original Gate Keepers, now grown up, are around as commanders, mentors and even parents to the new cast, and.
 * Miwa "Micchi" Uzuki, The Chick in the original Kotetsu Jeeg, becomes The Captain in the Revival, Koutetsushin Jeeg.
 * The original cast in the Record of Lodoss War TV series after the time skip.
 * A variation occurs in Zeta Gundam where the The Rival of the previous series, Char Aznable plays the mentor role to Kamille Bidan.
 * This is subverted in Gundam Seed Destiny, wherein the previous cast end up in direct conflict with the new and still idealistic protagonists. They are older, and they are wiser, but it certainly doesn't do them much good when it comes to trying to convince the new cast of that.
 * In addition to Char, Amuro Ray, the protagonist of the first series, gets this as well in Zeta Gundam, but is a bit more angsty about it. Also in Chars Counterattack, he seems to have once again matured to a steel-willed veteran.
 * Another example of it happening backwards is in Mahou Sensei Negima, where some members of Ala Rubra, who saved the world 20 years ago, show up to help Negi on his way. Especially Jack Rakan. He's certainly Older. Wiser? Not so much.
 * The Digimon Adventure cast to the Digimon Adventure 02 cast. Four years separate the two.
 * And Taiki and Shoutmon from Digimon Xros Wars return to Digimon Xros Wars the Young Hunters Leaping Through Time as the smart mentors. Yuu himself returns from the previous series now matured as one of the main cast.
 * In Magical Girl Lyrical Nanoha, almost the entire cast of the first two seasons returns as Older and Wiser mentor figures to the newcomers in StrikerS. Nanoha specifically designs her training programs to prevent them from making the same mistakes that she did when she was younger.
 * Any characters that are around for longer then one arc in JoJo's Bizarre Adventure. Notable ones include Joseph Jostar, Jotaro Kujo, Speedwagon and Dio Brando.
 * Rad, Carlos, and Alexis from Transformers Armada return aged ten years older to play supporting roles in Transformers Energon.
 * Also, Hot Shot has gone from the Kid Appeal Character to one of the new Bumblebee's trainers (and is actually idolized by him for the first few episodes.)
 * Every new generation of Dex Holders in Pokémon Special will eventually be backed up by the older ones.
 * Smith in Ginga Densetsu Weed.

Comic Books

 * The DCU often has Golden Age superheroes filling this role, especially Jay Garrick (the Golden Age Flash) and Max Mercury to Wally West (the Post-Crisis Flash) and Impulse.
 * The X-Men are often shown as teachers to young, teenage mutants -- which many of the X-Men were when introduced.

Film

 * Don Diego Vega (Anthony Hopkins), the original Zorro, returns to train Alejandro Murrieta (Antonio Banderas) in The Mask of Zorro.
 * Frenchie from Grease returns to high school (yes, as a student) to be mentor to the next decade's New Transfer Student Michael Carrington in Grease 2.
 * Though only a few years older, Nancy from A Nightmare on Elm Street embodies this trope when she trains a new batch of imperiled kids to fight back against Freddy in Dream Warriors.
 * Obi Wan Kenobi over the course of the Star Wars films, who starts off as an apprentice to Qui Gon Jin, but becomes more of a wise and experienced Jedi master, culminating in him teaching Luke, his former padawan's son, about the Force in the beginning of episode IV. Luke goes through a similar development going from a whiny teenager in episode IV, to a wise, up-and-coming Jedi master himself in episode VI.

Literature

 * Henry in The Time Traveler's Wife managed to be an Older and Wiser mentor to himself.
 * Used in each subsequent Tortall series by Tamora Pierce. Especially Alanna (Song of the Lioness) to Kel (Protector of the Small), and George (Song of the Lioness) to Aly (Trickster books).
 * Done interestingly in Robin Hobb's works with Fitz, protagonist of the Farseer trilogy. He's still the narrator and protagonist when he returns fifteen years later for the Tawny Man trilogy, but the heart of the story is his attempts to guide and mentor the adolescent offspring of his old friends. So, for once, the Older and Wiser character remains the main character!
 * The Star Wars Expanded Universe has Ferus Olin, who was a contemporary of Anakin in the Jedi Quest series as a teenager, was a young adult and the main character of the Last of the Jedi series, and returned in the Rebel Force books to serve as on-again-off-again mentor to Luke and Leia. He does indeed have a Heroic Sacrifice and a genuinely moving death scene.

Live Action TV

 * Sarah Jane Smith in The Sarah Jane Adventures. Explicitly shown in "Turn Left":.
 * Tommy in Power Rangers Dino Thunder, who returns to superheroing as the team mentor figure after taking seven years off for college, graduate school, a doctorate program, and wildly successful research on superpowered dinosaur cyborgs. It is unknown, but doubtful, if the character slept between his departure in 1997 and return in 2004.
 * Barney Collier from Mission Impossible appeared in some episodes of the revival series, while his son was one of the main characters (and their actors were father and son, too).
 * Steed in The New Avengers
 * Although Welcome Back, Kotter didn't have any prior show, the character Gabe Kotter was a former student who comes back to his high school alma mater to teach an often unruly group of remedial wiseguys known as the "Sweathogs", of which he was a founding member.
 * Colonel Samantha Carter is promoted from a member of the Five-Man Band in Stargate SG-1 to the leader of the Atlantis Expedition in Stargate Atlantis. The timespan is a bit shorter, but the concept is the same.
 * Lieutenant General Jack O'Neill takes on this role in Stargate Universe.
 * When Faith first appears in Buffy the Vampire Slayer she's a cynic, a Blood Knight and especially because she is a Slayer she can have and do whatever she wants. Now she tries to teach other Slayers that With Great Power Comes Great Responsibility and With Great Power Comes Great Insanity, is on the lookout for those who might go Knight Templar, and is insightful enough to know that Angel created monsters, and tears himself up over having to live with them.

Theatre

 * Although still technically the main character, Oedipus of Oedipus at Colonus has completely transformed from his portrayal in Oedipus the King and provides a contrast with the rest of the cast which is younger.

Video Games

 * Ryu and Ken in Street Fighter III, and Terry Bogard in Garou: Mark of the Wolves
 * Solid Snake in Metal Gear Solid 2, since he'd become so Badass that it could no longer be constrained by the limits of gameplay.
 * The Moon Angels in Galaxy Angel II.
 * Dekar of Lufia II joins the party in Ruins of Lore, but calling him wiser may be a bit of a stretch...
 * Bleu (Deis) from the Breath of Fire series, especially in Breath of Fire II (provided that you can find her...) where she proves to be one of the best spellcasters in the game.
 * Averted in Fire Emblem Radiant Dawn in which the cast of Path of Radiance all make appearances as major characters and despite some maturity still have their own problems and issues to deal with.
 * Finn and Oifey, from Genealogy of the Holy War, are straighter examples ; you had them in the first generation as young apprentices, in the second generation they are back as mentors to Leaf and Nanna, and Celice and the other children at Tilnanogue respectively. Levn, who comes back as Celice's strategist, also counts, though this may be because of his
 * Dante in Devil May Cry 4.
 * Not exactly, due in part to the confusing ordering of the series and in part to Dante's tendency to be a wiseguy rather than a wise guy.
 * Actually, it's zig-zagged due to Dante acting as both a Stealth Mentor and Trickster Mentor towards Nero. And to be fair, 4 is the latest game in the timeline if you don't count second the second game.
 * Phoenix Wright in Apollo Justice: Ace Attorney. Some argue that this transition wasn't entirely natural, however...
 * The main character of Dig Dug, to the main character of Mr. Driller.
 * Rydia from Final Fantasy IV. She joins the party as a child, and when the ship your party is on gets destroyed, she is taken to the Land of Monsters, where time flows faster than in the regular world. When she rejoins the party later in the game, she is a fully-grown adult, complete with additional powers.
 * Auron in Final Fantasy X would fit this trope perfectly, except we see it backwards. Near the beginning, he emerges from obscurity to join the younger crew and teach them what's what, but only as the game progresses do we gradually learn what happened the first time around.
 * Dark Forces/Jedi Knight series hero Kyle Katarn becomes the mentor to new player character Jaden Korr in Jedi Academy.
 * In The Legend of Zelda: Twilight Princess, the Hero's Shade teaches Link several advanced sword techniques, and there are multiple nods at him being a previous Link (eventually confirmed to be the one from Ocarina of Time).
 * Similarly, Ganondorf himself returns older and wiser in The Wind Waker, now sporting a surprisingly effective Beard of Evil, having become much more calm and calculating than he was in his youth, preferring to control events from the shadows as opposed to in everyone's face with his magic and hordes of evil. Fittingly, however, he reverts to his fury of the old days during the final battle.
 * Sonny Bonds, the hero of the original Police Quest Sierra point-and-click adventure games, is your SWAT unit's commanding officer in the tactical First-Person Shooter SWAT 4.
 * For the record, that means the last time we saw him, he was a Detective Sergeant in Homicide. A minimum of ten years later (due to physical SWAT requirements), he has been promoted to the rank of Captain. At least. One hell of a meteoric rise.
 * Liese in Atelier Annie. Not that you'd be expected to know. She's also.
 * Leo Stenbuck from Zone of the Enders, returning in The Second Runner less mopey and with added levels in Badass.
 * Flik and Viktor in Suikoden II.
 * The Donkey Kong series has Cranky Kong, who was the Donkey Kong from the original arcade games. Unfortunately, while he's older and wiser, he's so much so that he's more Grumpy Old Man than anything else.
 * Peppy Hare, from Star Fox, is seen as this, having been part of the original Star Fox Team. He even gives up piloting his arwing after Star Fox Adventures.
 * Soul Calibur has at least two examples:
 * Siegfried changes from an arrogant bandit from a knightly background who unknowingly murders his own father and winds up letting Soul Edge turn him into the next Nightmare, to a regretful and determined paladin-like figure determined to redeem himself even in the face of horrific crimes and almost certain death.
 * Seong Mi-na is the same age as Siegfried, and starts out as a naive and Hot-Blooded girl. In later installments, Yun-Seong looks up to her as a Cool Big Sis, and her father remarks that she has grown.

Webcomics

 * Clark from Shape Quest, who complains that they feel he's way too old for adventuring, despite being 35.

Web Original

 * Yamauchi-sensei from Greek Ninja.

Western Animation

 * A now old and retired Bruce Wayne in the futuristic Batman Beyond.
 * Egon in Extreme Ghostbusters (while his three colleagues made a cameo Not as You Know Them).
 * A rare villainous example is Ravage from Beast Wars. One of the last surviving original Decepticons from the era of the Cybertronian Wars (a.k.a. the original cartoon), he's moved up in the world since we saw him last, and he learned a thing or two from his millenia of war.
 * Also, the Time Skip between the original 'toon and movie has Spike going from Tagalong Kid to adult who has a son who's the new Tagalong Kid.
 * In the Futurama film Bender's Big Score,