SUPERGIRL

SEASON 3: GIRL OF STEEL (2017)
Kara dreams of life with Mon-El on an alien world.

SEASON 3: TRIGGERS (2017)
Kara battles a powerful metahuman called Psi, who can evoke her victims' deepest fears, forcing Supergirl to feel guilt over Mon-El.

SEASON 3: DAMAGE (2017)
Several children are diagnosed with lead poisoning. Industrialist Morgan Edge publicly blames Lena's lead device which repelled the Daxamites. But in reality it was a chemical from one of Morgan's companies.

SEASON 3: WAKE UP (2017)
Mon-El is discovered in a crashed ship with several occupied stasis tanks inside. He explains his pod went through a wormhole to the 31st century, where he's been for the past seven years. He frees one of the people from the tanks: his wife Imra Ardeen.

SEASON 3: CRISIS ON EARTH-X PT 1 (2017)
Supergirl defeats a rogue Dominator. Later, she and Alex travel to Earth-1 to attend Barry Allen's wedding with Iris West, where a nervous waitress attends to guests. As will be revealed later, she is the speedster XS, Barry and Iris' daughter from the future. The storyline then continues into ARROW and THE FLASH, but there are no Legion-related appearances there.

SEASON 3: REIGN (2017)
Mon-El and Imra explain how their ship came from the future and how the former founded the superhero team, the Legion.

SEASON 3: LEGION OF SUPER-HEROES (2018)
Kara is critically injured by the villainous Reign. Mon-El releases Brainiac 5 from his stasis tank to heal her. Mon and Imra don their Legion costumes and tackle Reign.

SEASON 3: FORT ROZZ (2018)
Brainy and Winn start to bond, as do Supergirl and Imra.

SEASON 3: FOR GOOD (2018)
Mon-El and Supergirl tackle Lena's mother Lillian, who's wearing Luthor's exoskeleton armor.

SEASON 3: BOTH SIDES NOW (2018)
Mon-El tells J'onn more about the Legion's origins, and also confides that he still has feelings for Kara despite loving Imra as his wife.

SEASON 3: SCHOTT THROUGH THE HEART (2018)
Mon-El brings down a giant robot dinosaur with some neat cape tricks, while name-dropping Rimbor.

SEASON 3: IN SEARCH OF LOST TIME (2018)
Mon-El dons his old costume, now modified by Winn, and trains Supergirl in the art of using capes for battle.

SEASON 3: OF TWO MINDS (2018)
The being named Pestilence infects people with a virus that Mon-El compares to the Blight of the 31st century, and Imra says it was a big problem on Winath. Imra manages to gain a blood sample from Pestilence for Brainiac to manufacture a working cure.

SEASON 3: TRINITY (2018)
The Legionnaires, Supergirl and DEO discuss ways of defeating the villainous Wordkillers.

SEASON 3: SHELTER FROM THE STORM (2018)
Imra tells Supergirl more about the Blight, saying Chameleon was the first to fall. Then Brainy put the remaining Legionnaires into the stasis tanks until a cure could be found. The Legion ship, now repaired, returns to the future, but Mon-El decides to stay behind.

SEASON 3: THE FANATICAL (2018)
Mon-El and Kara fly J'onn's spaceship to travel to a meteorite to find out more about black Kryptonite.

SEASON 3: DARK SIDE OF THE MOON (2018)
Kara and Mon-El reach the meteor and discover there is a city on it. Supergirl soon realizes it's a surviving part of Krypton, Argo City, and that her mother Alura is living there.

SEASON 3: NOT KANSAS (2018)
Kara and Mon-El defeat Reign and her body disintegrates. Kara decides to return to Argo City to be with Alura and invites Mon-El to join her.

SEASON 3: MAKE IT REIGN (2018)
Reign is not yet dead and Supergirl and Mon-El, visiting Argo, use Alura's hologram crystal to discuss battle plans with Winn back on Earth.

SEASON 3: BATTLES LOST AND WON (2018)
As Reign attempts to terraform Earth into new Krypton, Imra and Brainiac 5 return from the future to help. After Reign is finally defeated, Brainiac 5 decides to stay on present-day Earth because a distant relative has started wiping out all other AI, and asks Winn to take his place with the Legion. Winn accepts his offer and travels to the future with Mon-El.