Base Breaker: Nick. Either an OK Red who has issues with confronting problems (Namely, fans criticize that Nick runs away from all of his problems and frequently gives up), or one of the largest Canon Sue characters ever made by Power Rangers (Which this page is biased towards).
Koragg. Either a legitimately interesting villain, a Token Good Teammate, or a poor man's Villamax, whose honor does not work as he works with evil forces with no shades of grey?
While Xander is still one of the most popular characters in the season, several fans have pointed out how he has Aesop Amnesia (In that he learns three times to stop being an arrogant jerk, but it never catches on)l
Creator's Pet: Nick is seen by some as being this, with many also calling him a Canon Sue. The final episode takes steps to remove him of this status though, by having him give up instead of trying to fight The Master. Although it quickly steps away of removing him from this when the other rangers say he's their only hope and has "always been the one to hold them together", despite alot of evidence to the contrary.
Crossover Ship: While not a romantic one, Chip and Dustin from Ninja Storm are commonly best friends in fandom due to being the nerd of their teams and for being the only male yellow Rangers (Which is commonly lampshaded during fanfics).
Fridge Brilliance: The final scenes of the season show the humans of Briarwood accepting the magical creatures that inhabit the forest. This could potentially have helped sow the seeds for SPD, wherein humans and aliens live (mostly) together in harmony.
Fridge Logic: In the "Dark Wish" three-parter, Imperious captures Jenji and wishes that the Mystic Force rangers never got their powers. The result is that history is rewritten: the villans, led by Imperious, conquered the world on the day that the rangers were supposed to get their powers (four months ago), and nobody remembers the pre-wish world besides the five rangers, Jenji, and most of the villans including Imperious. However, logically speaking, if the rangers never got their powers, Imperious and Jenji would still be trapped in the cave that only the rangers could open. Additionally, Morticon is absent from the post-wish world and would be alive if there were no rangers to kill him.
Ensemble Darkhorse: Xander, maybe it's the accent, maybe it's the wannabe Loveable Rogue vibe his smarminess gives off, maybe it's just the color green. When Operation Overdrive had a multi-season team-up episode instead of a full two-team crossover, Xander was the one brought in from Mystic Force. He's so much this that they had another Green Ranger get a promotion to Red Ranger.
Chip, while less popular, still has a notable fanbase, primarily due to being one of two yellow Western Rangers who's a guy alongside Dustin (Super Sentai had plenty of yellow males before, but Saban commonly changed them to women when adapting seasons). His boundless enthusiasm, particularly at getting the chance to become a Power Ranger, is also a notable characteristic that helps him stand out from others in the series.
Genius Bonus: The Manticore Megazord is based on a obscure mythological beast with the body of a lion, a human face, bat wings, and a scorpion tail. The Megazord is lion-based for the most part, but cheating with being part-firebird, has a human-like face like all megazords, grows wings of fire before using it's finishing move, but no tail.