Leni Loud (seasons 5-present)

Leni Loud is one of the titular main characters in 1st-4th season and the titular deuteragonist in 5th-present season of the Nickelodeon series The Loud House. While she was tolerable for the most part in seasons 1-4, she has received flanderization in season 5, but became a little bit more likable in season 6 (depending on your view).

Bad Qualities

 * 1) Like Lincoln, she became flanderized. But unlike him, she went from a compassionate teen to an even dumber person. Now granted, Leni was the airhead of the show, but she wasn't that stupid in the earlier seasons, not even to the point of being very dumb to the point it's not even mostly funny anymore. Sound similar?
 * 2) In "Schooled!", she acts like she lost all of her IQ, as she confused high school with preschool. This is considered not just the stupidest moment she has done in season 5, but in the entire series. It does not help that this would later be put back in "Appetite for Destruction" as a callback, as if the writers didn't learn their lesson from "Schooled!" and the fans.
 * 3) She has become even more irresponsible in season 5 as well.
 * 4) *She mostly has clumsy/accident-prone moments and is a true butt-monkey in the series due to her ditziness.
 * 5) In "Electshunned", she tried to run for mayor of Royal Woods despite the fact she's a minor and and not even a politician. Thankfully, she quit in the end and was nice.
 * 6) *She is at her absolute worst in the episode "Grub Snub" where she makes such a big deal of Lincoln and his friends hanging out at Gus' Games and Grub and then she tries to get Lincoln to leave Gus' Games and Grub. In fact, during the final round of their challenge, all of them start fighting and destroying all the arcade games which causes everyone else to run away from Gus' Games and Grub. They even injured the owner, Gus Gamesngrub and somehow are allowed back in the arcade instead of being banned.
 * 7) What makes it worse is that in season 4, she actually started to get a little smarter in that season, which was pretty good character development. But in season 5, it is almost all thrown away, but got a bit of it back in season 6 (depending on your view).
 * 8) Her voice in the A Loud House Christmas, Dora Dolphin, sounds nothing like her original actress. In the upcoming live-action series, there is a possibility that she will be replaced, where it was eventually confirmed to be true.

Good Qualities

 * 1) She was better in seasons 1-4 and as mentioned above in the description and BQ#5, depending on your view, she improved a bit in season 6, as she isn't as dumb there, similar to Lincoln Loud improving himself a bit in Season 5. Also, Liliana Mumy still does a wonderful job voicing her.
 * 2) She still has her original personality in several episodes, such as in "The Boss Maybe" and the end of "Electshunned".
 * 3) *In "Schooled!", she shows Lily her preschool pictures. Later, she is shown boncing at the preschool, telling her parents that she will go to high school after five more bounces.
 * 4) At least she still cares for her friends and still has nice relationships with his family, especially Lincoln.
 * 5) Like modern Lincoln Loud, she still has her fair share of funny moments.
 * 6) She still has a likeness to designing outfits and accessories to go with them, making them look pretty, much like the first four seasons.
 * 7) She finally got her driver's license and able to drive Vanzilla completely in "Driver's Dread" after she passed her driving test.

Trivia

 * Starting in season 5, she is now the deuteragonist of the series (replacement for Lori) due to Lori is now moving out from Royal Woods to attend Fairway University with her friends and starts 12th grade.
 * Since in season 6 episode "Driver's Dread", she finally got her driver's license and able to drive Vanzilla completely after she passed her driving test.