Human looking villains: the dilemma about how to handle them, both from the heroes's point of view and the series's crew point of view

In Super Sentai, like in most tokusatsu, we have heroes fighting monsters, or robots, or whatever to protect other people and Earth's peace. However, while the MOTW are usually played by suit actors and seiyuu (or when they have an human appearance, it's merely a disguise, and their true monstrous nature is soon revealed), in a lot of cases, the main villains are played by live actors or actresses, and, thus, the enemy is human looking.
This element raises several questions :
- how do the heroes behave, seeing that their enemy has in fact a human face like them, or even is indeed human : do they have the right to kill that enemy like it was a mere beast or destroy it like a machine.
- How do the producers and writers are dealing with the fac tthat they show in a kid show heroes fighting and even potentially killing a character who looks human ( and especially if the character is female or a kid) ?  While during most of the show, the question can be dodged, since the main antagonist has to survive, how do they deal with it towards the end?

In Super Sentai, several situations can occur for human looking villains :

A) Looking human, but not human

1)  In a lot of cases, the antagonist may look human, but is obviously not human : he or she is either a robot/ cyborg, a monster/ demon, a ghost, or even sometimes a mere composite avatar (like in Go-Busters); they also can be aliens, and that group of aliens is completely evil.

I'm gonna give some examples
- in the robot/ cyborg/ avatar  category : Iron Claw (JAKQ) , the Zero girls (Sun Vulcan) , the Big Three  and Farrah Cat (Bioman), Shibolena (Megaranger), Enter and Escape (Go-Busters)
- in the monster/demon group : all the Jashinka (Dynaman), Ley Wanda, Ley Nefel, Urf, Kilt (Flashman), Lehda and Jarmin (Turboranger), Radiguet (and arguably Tran/Tranza), Lami (Zyuranger), Junior, Dr Yugami and the Hanarangers (Kakuranger), Dinas (GogoV), Tsue Tsue (Gaoranger), Vancurya (Magiranger), Gaja (Boukenger), Long (Gekiranger), Kegaleshia (Go-onger)
- evil aliens : the Vader Clan (Queen Hedorian, General Hedrer, Keller, Mirror and Amazon Killer), Ser Kaura (Flashman), all human looking villains of Zone (Fiveman), Shelinda (Gingaman), Wendinu and Furabijou (Hurricanger), Basco (Gokaiger)

In most of those cases, the heroes don't see those characters as human, and fight them as if they weren't human looking, because they know they're not human : the only way the heroes may stop the fight would be if those characters showed a behaviour that would make them potentially redeemable, which is very rare.
In those cases, the crew indeed doesn't really care if the heroes kill those characters: after all, their human guise is just a disguise: more often than not the antagonist is defeated in a monstrous form.

B) Aliens in an universe where the concept of good aliens is aknowledged

In several sentai shows having aliens as antagonists, the society where the heroes come from aknnowledge the fact that not all aliens are evil and that good aliens are in fact the majority : in those cases, human and not human looking villains are treated the same again, but the idea of redeeming villains is more prominent

Examples: in  the two police themed sentai, Timeranger and Dekaranger, while the enemies are aliens, there are also aliens among the allies (Timegreen, Dekamaster, or supporting characters): in those cases, the heroes's actions against the aliens must be justified: in Timeranger, the heroes merely want to bring the aliens back to jail; in Dekaranger, the aliens are criminals who can only be destroyed (deleted) if a space court give the heroes the greenlight.
Two Soda shows also explored the concept in depth:
- Changeman, where the Gozma are only some aliens among a lot of different ones (Ibuki, the heroes's boss, is himslef an alien), and even the Gozma themselves are forced to fight because of an horrible blackmail by their evil boss: the show tries to give the viewers empathy for the aliens, be them human or not human looking, and at the end, the heroes try to defeat the Gozma as much as they try to save their enemies from Bazoo's tyranny (successfully in the case of Shima, Gator and Gyodai, which have shown potential for redemption)
- Maskman : likewise, the Tube isn't an all evil society, but has been corrupted by an evil ruler, Zeba : while most of the generals are evil, the main hero is in love with the princess of the Tube kingdom, and several Tube members have been shown as good people.

Another case may be Dairanger, with the conflict Dai/Gorma : but once again, the concept of having to try to have a peace, or at least a truce with the Gorma is also highlighted (especially with the reveal that Kaku, the heroes's mentor is himself a Gorma)

How does the heroes deal with those kind of villains : usually, once again, as long as the enemies behave in  an completely evil way, the heroes have no trouble fighting them: but as soon as they may show some redeeming potential, they're gonna try to save them. The gender of the villain can also be important : the heroes are more likely to try to save a beautiful woman (Shima or Igam).

How the crew deal with it : in a lot of cases, the villain may be saved from death (Igam, Shima, Gator), or they are killed by the heroes in a fair fight (Baraba, Giluke) or they are dying victim form either other villains or other reasons (Ahames, Fumin, Akomaru (the two latter die in a cave in) ) ; Dairanger is a weird case where most of of the human looking Gorma are revealed to be clay copies.

 Special case: Carranger: the Bowzock are shown as being more silly than evil, and the human looking one's (Zonnette) main arc is her crush on the Red Ranger. In Zonnette's case, Red Racer must struggle with how to deal with an enemy in love with her ; of course, Zonnette is revealed to be really a good princess and most of the Bowzock survive.

C) Enemies are human, or at least seen as humans by the heroes

Those cases are the ones which are creating the most difficulty to the heroes.
Exceptions:  Hedda and Salome from Battle Fever J and most of Deathdark for Goggle Five; while they're not shown as really non human, the question is never raised in the show, and they're fought as if they weren't human.

However, there are several cases where the enemy is indeed human, and often, someone who is very close to the heroes : several shows focus a lot on that. In a lot of cases, those antagonists are evil rangers.   (for each show, I'll detail first how the heroes deal with the situation, and then, how the writers/ producers deal with it):

- Liveman: the whole point of the show is the fact that the enemies are the heroes's former friends, and the Liveman have to struggle with the fact that their friends are evil killers, and that they have to fight them : in a lot of cases, the memories of the time where they weren't evil yet make the fight even more difficult, and the heroes are often tempted to try to redeem them whenever they feel that can work (and they succeed in one case, with Gou/ Dr Obler) ; interestongly, in Liveman, none of the human looking villains is killed by the heroes: they're either dying through suicide (Ashura, Mazenda), or they die as a result of their actions which eventually backfire, and results in their death (Kemp, Bias)
- Turboranger : as half demons, but also half humans, Yamimaru and Kirika are seen as fellow humans by the Turborangers, especially during the Kirika era, since Kirika was a former friend of Riki and Shunsuke. Once again, while they are often fighting the two Hanyo, several times, the issue of saving them instead of killing them is raised: eventually, both characters turn on the good side and survive.
- Zyuranger : Burai, the evil Dragonranger is first an antagonist, but as soon as Geki learns Burai is his older brother, he's torn between his duty to defeat him to stop his evil actions and try to save him because of his fraternal love: eventually Burai turns good : while he dies some months later, he dies as an hero.
- Hurricanger : the Gouraigers are at first evil, but the Hurricanger see them as fellow survivors from th Jakanja attack, and they really want them to switch sides instead of fighting them : starting with episode 18, the Gouraigers are good guys
- Abaranger : a complex case, since the human looking villains are Jeanne and Lije, who are revealed to be Abareblack's wife and daughter, and Mikoto Nakadai/ Abarekiller, who has been the surgeon who saved Abared's life before becoming his enemy. Like Liveman, Abaranger raises the question about how to deal with villains with such deep connections to them ; at first, Abareblack was able to fight Jeanne only because he thought Jeanne was a monster using his wife's body; however, when he realized the truth, he couldn't fight her anymore like before; the heroes have no idea how to deal with a enemy who is a little girl: and the core point of the Abarekiller arc is to describe Ryouga's struggle to deal that a human, and the very doctor who has saved him is his enemy and that he may have to defeat him to protect Earth; the struggle was even harder because Abarekiller also did everything to make it more difficult for him.
Eventually, Jeanne becomes good midway through the show and becomes a valuable ally; she plays also an huge role in saving Lije, her own daughter from the Evolian. Eventually, because of his furor against the Evolian, Nakadai becomes the Abaranger's reluctant ally and plays a key role in the final fight; however, he ends up dying.
- Jetman also has Maria, who is really Red Hawk's true love, Rie ; at first, he thought that Maria wasn't Rie despite looking like her, so he was able to fight her. However, as soon as he learnt the truth, Ryu wasn't able anymore to fight Maria, and several episodes (notably episode 42) had him having protective behaviours towards Maria, despite her antagonistic behaviour. Eventually, in her last episode, Maria becomes Rie again, but dies at the hands of Radiguet, deeply suffering from guilt.
- Gekiranger : Rio was a former comrade of Jan's father, Gou (Gekiviolet) and Miki (the Gekiranger's female mentor : however, he turns evil and Gekiranger deal a lot with the fact that the Geki Jyu Ken has to fight a former pupil, and their struggles about how to handle it. Gekiranger gives the viewers a lot of empathy towards Rio. At the end, Rio realizes that he's been manipulated by a real evil force (Long) and finally reconcile with the heroes in order to fight him. Once again, the team has issues about dealing with Rio, but finally, Rio dies a heroic death fighting Long. Mele, a female follower of Rio, is written as a devoted sidekick and sometimes comic relief, and pretty much follows Rio's path.
- Kakuranger : Tsuruhime has to struggle with the fact her father is working for the Yokai ; while in fact her father was in fact in her side, she only learns it much later, and even then, she's forced to fight him and has to struggle with that reality. (Jiraiya has also a short arc where he has to fight his father figure)

In all those cases, the fight that the heroes have to do is very hard because of their links with the villains, and these struggles often makes very interesting plots

Special case about the three mad scientists : Dr Man from Bioman, Lee Keflen form Flashman and Dr Hinelar from Megaranger : all three are humans, and Dr Man is the father of a kid who is the Bioman's friend, and Dr Hinelar was a former friend of the Megaranger's mentor, Dr Kubota.
In those three cases, the scientist was completely corrupted and evil, and the heroes had no choice but to defeat him.
Bandora from Zyuranger was a former good queen, who became corrupted after her son's apparent death; at the end, she's merely sealed with her followers but not killed.
Another weird case is Shizuka from Boukenger ; despite being evil and never stopping in her villainous way, she's more written as a comic relief villainess and she is never  really targeted by the heroes who merely try to stop her instead of kill her; the fact that she's a cute girl might be the reason why the staff doesn't want to kill her. 

D) Heroes dealing with human villains in other toku shows

In several Metal Hero shows, especially the Rescue Police era (Winspector, Solbrain), the villains aren't monsters, but humans; in those cases, most often than not, the heroes merely arrest the criminal, and if the criminal dies, it's a result of his own actions. It must be mentioned that Janperson dealt with some evil humans (Reiko from the Super Science Network, but, most importantly, the Tatewaki Company with Ryousaburo Tatewaki/ Bill Goldy and his secretaries/ hitwomen who were completely evil, and that Janperson eventually had to kill)

In Kamen Rider, two shows especially used villains that were in fact humans; who only became monsters thanks to speciall deviced : Kamen Rider W and Kamen Rider Fourze. In both shows, the aim of the hero wasn't to kill the monster but to destroy the device who was making them become monsters. As a detective show, most of W's antagonists were arrested soon after being defeated; in some cases, the former monster( Dopant) was let go because he or she was more a victim than anything else; and Philip (one of the heroes) has to deal with the fact that the main villains are none other than his true family, and the final arc deals mostly with Philip's struggles.
In Fourze, all the Zodiarts (the antagonists) were in fact either fellow schoolmates of the main hero and his allies, or members of the school's crew. Besides, a good bunch of them were more victims than anything else, and Gentaro's aim was to become friends with them, even if he had to figh them before. In fact, his behaviour is mostly successful, and we see a lot of former Zodiarts show later a friendly behaviour towards their former enemy. The biggest symbol is when Gentaro offers his friendship to the leader of the Zodiarts, despite everything he did, and even succeeds in earning it.