These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: Back Dimensional Count Radiguet is a sadisticAx-Crazy genocidal maniac with megalomaniacal fantasies of ruling the Vyram under an iron-fisted dictatorship. Even when Juza, his boss and the true Big Bad, arrived he planned to overthrow her but that failed. Afterwards when it looked like he would become good because of a sick girl (who became his Morality Pet while he had amnesia) whom he cured unknowingly he spurned her offer to turn good by killing her. All because she believed he could feel love. He's also the one who brainwashed Rie into being Maria for no other reason For the Evulz. His most repulsive Kick the Dog moment was when he killed her after she snapped back to being Rie. There's also the part where he tortured Tranza until he became insane and was left at the door of an asylum.
"Funny Aneurysm" Moment: One of the episodes is titled "Gai Dies!". He came back after that. Guess what REALLY happened to him in the ending.
Epileptic Trees: Lots of them, especially on theories that support that Gai is not dead from that one stab. Or how Radiguet actually survived, left permanently powerless as a human, and then became the thug that stabbed Gai.
He's Just Hiding: Some people still believe that after surviving the battles and explosions against Vyrams, one thug's mere stab isn't enough to kill Gai.
If you take the events of "Super Sentai World" as canon, he is still alive...Though it could also be taken that Super Sentai World takes place before Ryu and Kaori get married, thus Gai would get stabbed soon.
In the 2013 Gatchaman movie, the actor who played Shinken Red will also play as Ken the Eagle, whom in turn is the inspiration for Red Hawk.
Ho Yay: Especially early on, between Ryuu and Gai.
Ryuu: Behave yourself, Gai. I'll date you. Later Gai: Why can't I get that guy out of my head!?
Jerkass Dissonance: In one episode while the group is out shopping, Gai decides to grab Kaori by the arm, drag her away from the others against her will, shove her into an elevator to isolate her from everyone else, and then invade her personal space as he demands to know why she doesn't love him instead of Ryu. Despite this and many more actions like this, he is one of the most popular characters in the whole of the Super Sentai franchise.
Moral Event Horizon: Episode 18, for Radiguet. He loses his memory of being a Vyram after being banished by Juza, and is found by a girl who falls in love with him. The girl is terminally sick and has been diagnosed with only six months to live. Radiguet, realizing he has supernatural powers and starting to fall in love with her too, manages to cure her. However, after stumbling upon Juza fighting the Jetmen, he remembers who he is, and wanting revenge, he helps the Jetmen kill Juza. Later, the girl, having witnessed his transformation, tries to persuade him to abandon his evil ways, saying that he must have some good in him since he cured her. He ignores her pleas and kills her.
He crosses it again in Episode 49. He kills Maria, after reverting to Rie, in front of Ryū...but not as a punishment for traitors, but just so Ryū won't get the girl he's after.
No Problem with Licensed Games: The Jetman game for the Famicom is considerably decent by licensed games standards, if a bit shallow. The developers, Natsume (of Harvest Moon fame) went on to develop the all of the Power Rangers games for the SNES (including the Gekisou Sentai Carranger game for the SuFami Turbo Super Famicom add-on), as well as some of the later Game Boy Color/Advance ones.
Squick: crystals growing out of the victims' bodies. Graphically. Ick.
Strangled by the Red String: Ryu and Kaori get married at the very end of the series, despite Ryu spending the whole series pining after Rie and Kaori spending the second half of the series with Gai. The wedding takes place two years after the battles with Vyram are over, so there must have been great development during those two years we never got to see. Still pretty odd, and could have been handled better.
What an Idiot: When Tranza built and deployed his enormous robot, Veronica, it was clear that the Jetmen didn't stand a chance against it. Then, for some inexplicable reason, Radiguet decides that the best time to betray Tranza is just before Veronica lands the killing blow, allowing the Jetmen to survive and ultimately destroy the robot. If Radiguet had waited for the Jetmen to be killed and then betrayed Tranza immediately afterward, he would have achieved his goal of becoming leader of the Vyram and conquering earth.