History Recap / Supergirl2015S3E17Trinity

* FreakyFridayFlip: Sam does this to ''herself'', by taking control of Reign's body for a brief amount of time. Unfortunately, this also means that Reign takes control of Sam's body in Juru, giving her free [[IncrediblyLamePun reign]] to hurt the protagonists.

* TotalEclipseOfThePlot: The World Killers cause an eclipse during their ritual to purge their human selves, which will eventually have the side effect of ending all life on the planet. Stopping them before the eclipse is complete and Supergirl is rendered powerless becomes vitally important. (It is also briefly stated that [[ArtisticLicenseAstronomy the eclipse will cause a major temperature decrease]].)

* ArtisticLicenseAstronomy: Solar eclipses do not cause substantial temperature drops on Earth as suggested in the episode. A lack of sunlight would ''eventually'' freeze the planet, but the episode makes it sound like it would happen instantly. And, since Kara doesn't lose her powers at night, the blocking of the sun's rays by an eclipse should not immediately impact her powers as it does. The latter is implicitly justified by magic, but the former is made to sound like a normal effect of an eclipse.

* FreakyFridayFlip: Sam does this to ''herself'', but taking control of Reign's body for a brief amount of time. Unfortunately, this also means that Reign takes control of Sam's body in Juru, giving her free [[IncrediblyLamePun reign]] to hurt the protagonists.

* JumpedAtTheCall: Villainous example: When told that they must purge their human selves to fully become World Killers, Pestilence doesn't hesitate to sever whatever metaphysical lifeline was keeping Grace breathing.

* OffingTheOffspring: The episodes ends on a {{cliffhanger}} showing Reign being told to kill Ruby.

* AllForNothing: Lena is heartbroken at the beginning, since all of her research on Reign was basically rendered useless and she strained her relationship with Supergirl in the process.

* ArtisticLicenseAstronomy: Solar eclipses do not cause substantial temperature drops on Earth as suggested in the episode. And, since Kara doesn't lose her powers at night, the blocking of the sun's rays by an eclipse should not immediately impact her powers as it does.

* TotalEclipseOfThePlot: The World Killers cause an eclipse during their ritual to purge their human selves. Stopping them before the eclipse is complete and Supergirl is rendered powerless becomes vitally important. (It is also briefly stated that [[ArtisticLicenseAstronomy the eclipse will cause a major temperature decrease]].)

The DEO recruits Lena in their fight against the Worldkillers, but the alliance is an uneasy one.

* AnotherDimension: The DarkWorld Sam was sent to last episode isn't some MentalWorld confined to her own head, but another dimension all the Worldkillers are connected to.
* AntagonistTitle: The title refers to the three Worldkillers. Doubles as TeamTitle.

* HeroicWillpower: Julia and (briefly) Sam are able to overpower their Worldkiller personalities and take back control of their bodies.

** To a lesser degree, Lena also calls up Alex on keeping her own secret about working for the DEO.
* IKnowYoureInThereSomewhereFight: Alex towards Purity. Thankfully, Julia is able to break out in the end.

* JumpedAtTheCall: Villainous example: When told that they must purge their human selves to fully become Worldkillers, Pestilence doesn't hesitate to sever whatever metaphysical lifeline was keeping Grace breathing.

* NothingPersonal: What Lena claims her private Kryptonite supplies to be towards Supergirl. Alex responds that Kryptonite is ''very'' personal to Kara for obvious reasons.
* OffingTheOffspring: The episodes ends in a {{Cliffhanger}} showing Reign being told to kill Ruby.
* PsychologicalTormentZone: The valley tries to drive Sam and Julia insane, showing them the victims of their Worldkiller selves while their memories of all they know and love are slowly erased. They manage to resist with some help from Supergirl, Alex, and Lena.

* SplitPersonalityTakeover: In order to fully become the Worldkillers, Reign, Purity, and Pestilence have to kill off their human personalities. This is easy for Pestilence, since Grace was already on-board with the idea, but Sam and Julia are able to retain their sense of self and eventually regain control, if only briefly.
* SummonToHand: Winn built Alex's new outfit with magnetic palm pads designed to draw her gun back if she drops it. HilarityEnsues when it rips Brainiac's Legion ring right off his finger.
* TakesOneToKillOne: Reign boasts that only a being as strong as her can hope to kill her. Julia, after taking over control from Purity, realizes that she has the power to kill the other Worldkillers and does so with Pestilence, though Pestilence kills her in turn.
* TotalEclipseOfThePlot: The Worldkillers cause an eclipse during their ritual to purge their human selves. Stopping them before the eclipse is complete and Supergirl is rendered powerless becomes vitally important. (It is also briefly stated that [[ArtisticLicenseAstronomy the eclipse will cause a major temperature decrease]].)

** Lena in turn points out that Supergirl has secrets of her own, namely her secret identity, so she's hardly in a position to criticize Lena for having some. She also says something similar to Alex regarding Alex's involvement with the DEO.

--> '''Lena:''' That wasn't Lex's Kryptonite, I figured out how to make it.

* ArtisticLicenseAstronomy: Solar eclipses do not cause substantial temperature drops on earth as suggested in the episode. And, since Kara doesn't lose her powers at night, the blocking of the sun's rays by an eclipse should not impact her powers at all.

* InternalReveal: Lena learns that James is Guardian.

* TotalEclipseOfThePlot: The Worldkillers cause an eclipse during their ritual to purge their human selves. Stopping them before the eclipse is complete and Supergirl is rendered powerless becomes vitally important.

** Lena in turn points out that Supergirl has secrets of her own, namely her secret identity, so she's hardly in a position to criticize Lena for having some.

* OffingTheOffspring: The episodes ends in a {{Cliffhanger}} showing Reign about to kill Ruby.

--> '''Lena:''' That wasn't Lex's Kryptonite, I figured out how to make more.

--> '''Lena:''' That wasn't Lex's Kryptonite, I figured out how to make more.

* {{Hypocrite}} Lena points out that Kara is being one by lecturing her about keeping secrets:

* BeamOWar: Kara and Reign engage in an EyeBeams version during the fight in the Fortress.

* WhatTheHellHero: Supergirl and the DEO give Lena the third degree for her secret experiments on Sam and not telling them she was Reign. She was responds that 1.) the DEO doesn't technically exist and 2.) she's not J'onn's employee.
** Not just that she ALSO calls out Supergirl on keeping her experiments secret [[MoralMyopia yet Kara's okay with keeping her own name a secret]].

--> '''Lena:''' That wasn't Lex's Kryptonite, I figured out to make more.

** Not just that she ALSO calls out Supergirl on keeping her experiments secret [[DoubleStandard yet Kara's okay with keeping her own name a secret]].

The DEA recruits Lena in their fight against the Worldkillers, but the alliance is an uneasy one.

* NoGoodDeedGoesUnPunished: Lena's attempts to help Sam backfired big time. All she wanted to do was prove she wasn't "another Luthor".
* WhatTheHellHero: Supergirl and the DEA give Lena the third degree for her secret experiments on Sam and not telling them she was Reign. She was responds that 1.) the DEA doesn't technically exist and 2.) she's not J'onn's employee.

** Not just that she ALSO calls out Supergirl on keeping her experiments secret [[DoubleStandard yet Kara's okay with keeping her own name a secret]].

** Not just that she ALSO calls out Supergirl on keeping her identity a secret [[DoubleStandard yet she's okay with keeping her own name a secret]].

* WhatTheHellHero: Supergirl and the DEA give Lena the third degree for her secret experiments on Sam and not telling them she was Reign. She was responds that 1.) the DEA doesn't technically exist and 2.) she's not J'onn's employee.

* WhatTheHellHero: Supergirl and the DEA give Lena the third degree for her secret experiments on Sam not telling them she was Reign. She was responds that 1.) the DEA doesn't technically exist and 2.) she's not J'onn's employee.