Character rerailment

Character rerailment is the process of regaining the original personality of someone who was previously flanderized and becoming likeable again. It is the opposite of Flanderization and Derailment.

The Simpsons

 * Homer Simpson (Season 31-present; went back to being a dimwitted, yet well-meaning father after being flanderized into a moronic idiot who sometimes acts like a selfish jerk.)
 * Marge Simpson (Season 31-present; went back to being a loving, prepared, down to earth and strict mother after being flanderized into being a really overprotective mother worries too much about everything.)
 * Bart Simpson (Season 31-present; went back to being a mischievous, troublemaking, but a jerk-with-a-heart-of-gold type character after being flanderized into a borderline sociopathic jerk, as he didnt care about the health, safety, and lives of anyone.)
 * Lisa Simpson (Season 31; went back to being a level headed foil to Bart and the most mature out of the family after being flanderized into a complete know-it-all and a political soapbox.)

SpongeBob SquarePants

 * SpongeBob SquarePants (Season 8-present; became a friendly, optimistic, naive, immature (though sometimes mature when he needs to be), and free-spirited person again after previously being flanderized into an annoying, obnoxious, troublemaking, completely immature, idiotic crybaby.)
 * Patrick Star (Season 9b-present; went back to being a hilariously dumb, friendly, helpful, and fun-loving comic relief after previously being flanderized into a obnoxious, jerkish, and even dumber person.)
 * Mr. Krabs (Season 11-present; went back to being a greedy and flawed, but well-meaning businessman and an anti-hero after previously being flanderized into a more unlikable villain who was even greedier and less caring.)

Thomas & Friends

 * Thomas the Tank Engine (Seasons 17-24; went back to being a fussy, cheeky, optimistic and kind-hearted engine after being flanderized into a troublesome, irresponsible and unreliable engine who causes confusion and delay and never listens to Sir Topham Hatt. Unfortunately, he got flanderized again in ''Thomas & Friends: All Engines Go!.)
 * Percy the Small Engine (Season 17-24; became a friendly, caring, and naive softie again after being flanderized into an idiot who obsesses over Thomas's attention. Unfortunately, he was flanderized again in All Engines Go!.)
 * Gordon the Big Engine (Seasons 14-24; became a arrogant, pompous, but kind-hearted well-written Mean Popular Boy again after being flanderized into an immature, arrogant and unlikable character.)
 * Edward the Blue Engine (Seasons 17-24; became an old, wise, and friendly engine again after being flanderized into a paranoid wimp who is too scared to do anything.)
 * Toby the Tram Engine (Seasons 17-24; just like Edward, he became an old, wise, and friendly engine again after being flanderized into a paranoid wimp who is too scared to do anything.)
 * Henry the Green Engine (Seasons 17-24, became a kind and friendly gentle giant again after being flanderized into a coward who constantly worries too much about every little thing and is too stupid to do anything right.)
 * Emily the Stirling Engine (Seasons 17-24; became a friendly, mature, and kind-hearted voice-of-reason again after being flanderized twice into being bossy, naggy and selfish during S8-10, and an unintelligent Mary Sue in S12-16.)
 * Skarloey and Rheneas (Seasons 13-present; became old, wise, friendly, and brave engines again after being flanderized into reckless hyperactive children who like to race and fight over taking special trains during Seasons 9-12. Skarloey also became a wimp.)
 * Sir Topham Hatt (Seasons 17-24; became a strict, but kind hearted and reasonable ruler again after being flanderized into a pointless comic relief who messes up. Unfortunately, he was flanderized again in All Engines Go!.)

Battle for Dream Island

 * Gelatin (BFB 17-present); Went back from being an intelligent lovable scamp after being flanderized into an obnoxious prick who causes a lot of trouble for his teammates.

Others

 * Sakura Haruno (The Lastː Naruto the Movie, episodes after the Fourth Great Shinobi War and Borutoː Naruto Next Generations; went from being a very unlikable and whiny character into a strong, tender hearted hero and a great mother for her daughter Sarada Uchiha)
 * Ben Tennyson (Ben 10 (2016) season 5; went from being a rather annoying hero into a great kind hearted hero who acts more like his classic series counterpart.)