What If Nightwing lead the Arrowverse?

Nightwing
Airing: 2012-20

Seasons: 8

Plot: Fighting crime alongside the dark knight as Robin for ten years, Nick Grayson was growing tired of living in his adopted father's shadow and after a fight with Batman, Nick realizes he wants to be more than just Batman's sidekick. Nick and his girlfriend Barbara Gordon, under the new moniker of Batgirl move to Bludhaven to start fresh. Crimefighting isn't a walk in the park as Nick soon realizes and he is forced to question whether or not he is ready to fight on his own.

Protagonists:


 * Grant Gustin as Nick Grayson/Nightwing
 * Candice Patton as Barbara Gordon/Oracle
 * David Ramsey as Hank Hall/Hawk
 * Juliana Harkavy as Dawn Granger/Dove
 * Jesse L. Martin as Jim Gordon (S1-S6)
 * Jessica De Gouw as Helena Bertinelli/Huntress (S1-S4)
 * Willa Holland as Rose Wilson (S1)
 * Cress Williams as Jefferson Pierce/Black Lightning (S4-S6)
 * Rila Fukushima as Tatsu Yamashiro/Katana (S4-S6)
 * Ashley Liao as Cassandra Cain/Tigress (S7-)
 * Andre Braugher as HighFather (S8)

Antagonists:


 * Manu Bennett as Slade Wilson/Deathstroke (S1)
 * John Barrowman as Mark Desmond/Blockbuster (S2)
 * The Court of Owls (S3)
 * Willa Holland as Rose Wilson/Deathstroke (S4)
 * Cameron Monaghan as Roy Harper/Arkham Knight (S5)
 * Josh Segarra as Sheldon Lyle/Heartless (S6)
 * Alexander Siddig as Ra's al Ghul & The League of Assassins (S7)

The Flash
Airing: 2014-22

Seasons: 8

Plot: Wally West aka Kid-Flash was the sidekick to his uncle Barry Allen aka the Flash for five years. However, after a fight with the Reverse-Flash, the Flash has vanished. In the six months since his demise, Wally has denied the mantle, stating that he doesn't want to tarnish the legacy of the Flash, even going as far as to quit being Kid-Flash to avoid questions of where the Flash is. However, due to the absence of a hero to instill hope into the hearts of Central City, crime has spiked higher than ever before, forcing Wally to act... fast.

Protagonists:


 * Jordan Fisher as Wally West/The Flash
 * Malese Jow as Linda Park (S1-S4)
 * Danielle Panabaker as Caitlin Snow/Killer Frost
 * Carlos Valdes as Cisco Ramon
 * Danielle Nicolet as Iris West
 * Tom Cavanagh as Harrison Wells
 * Tyrel Jackson Williams as Danny West/Kid-Flash (S2-S4)
 * Violett Beane as Jesse Wells/The Flash (S2-S4)
 * Kyle Mooney as Ralph Dibny/Elongated Man (S5-)
 * Sarah Silverman as Sue Dearbon (S6-)

Antagonists:


 * Tom Cavanagh as Hunter Zolomon/Zoom (S1 & S8)
 * Teddy Sears as August Heart/Godspeed (S2)
 * Charles Michael Davis as Daniel West Sr./The Rival (S3)
 * Jordan Fisher as Wally West/Savitar (S4)
 * Chris Klein as David Hersch/Cicada (S5)
 * Neil Sandlands as Clifford DeVoe/The Thinker (S5)
 * Sendhil Ramamurthy as Ramsey Rosso/Bloodwork (S6)
 * Efrat Dor as Eva McCulloch/Mirror Monarch (S6)
 * Rick Cosnett as Eddie Thawne/Cobalt Blue (S7)
 * Tony Curran as Despero (S8)

Flash vs. Nightwing
Airing: December 2-3, 2014

Shows: Nightwing & The Flash

Plot: Roy Bivolo, a metahuman with the power to send people into an uncontrollable rage, uses his powers to rob the Central City bank. The police track Bivolo to a warehouse, where he uses his powers on a cop to facilitate his escape. Wally West arrives to save Darryl Frye, but is almost injured himself before Nick Grayson, as the "Nightwing" vigilante, arrives to stop the cop.

Antagonists: Paul Anthony as Roy Bivolo/Rainbow Raider

Supergirl
Airing: 2015-21

Seasons: 6

Plot: At 15 years old, Kara Zor-El escapes doom on planet Krypton to find protection on Earth. When Kara arrives, she discovers that 40 years have gone by. She now has to live in the new, cruel world that she is forced to face: high school. Having to now adjust to her new life, Kara must juggle her new responsibilities with her very human relationships as well as the superpowers that came with her from Krypton.

Protagonists:


 * Peyton List as Kara Zor-El/Supergirl
 * Nicole Maines as Alex Danvers/Sentinel
 * David Harewood as J'onn J'onzz/Martian Manhunter
 * Mateo Arias as Kenny Schott (S1-S3)
 * Mehcad Brooks as John Henry Irons/Steel (S1-S5)
 * Billy Unger as Logan Luthor (S2-)
 * Brandon Routh as Clark Kent/Superman (S2-)
 * Jordan Elsass as Conner Kent/Superboy (S2-)
 * Casey Cott as Mon-El (S3)
 * Jesse Rath as Querl Dox/Brainiac V (S3-)
 * Teala Dunn as Natasha Irons/Steel (S4-)

Antagonists:


 * Peter Fascinelli as Morgan Edge (S1)
 * Tyler Hoechlin as Paul Westfield (S2)
 * Tom Welling as Hank Henshaw/Cyborg Superman (S2)
 * Sofia Carson as Sam Arias/Reign (S3)
 * Peyton List as Linda Lee/Red Daughter (S4)
 * Jon Cryer as Lex Luthor (S5)
 * Thomas Lennon as Mister Mxyzptlk (S6)

War World
Airing: December 1-2, 2015

Shows: Nightwing & The Flash

Plot:

Antagonists: David Sobolov as Mongul

Teen Titans
Airing: 2016-22

Seasons: 7

Plot: On a mission to investigate a child trafficking ring, Tim Drake finds Rachel Roth, a special girl possessed by a strange darkness, and in an effort to save Rachel, gets involved in a conspiracy that could bring Hell on Earth. To combat this evil, Tim knows he won't be allowed to pursue this mission if an adult hero is accompanying him. As a result, Tim gathers fellow teen heroes and sidekicks across the country as together they become a surrogate family and team of heroes fighting evil.

Protagonists:


 * Leo Howard as Tim Drake/Robin
 * Cozi Zuehlsdorff as Rachel Roth/Raven
 * Karan Brar as Gar Logan/Beast Boy
 * Curran Walters as Bart Allen/Impulse (S1-S6)
 * Iñigo Pascual as Jaime Reyes/Blue Beetle (S1-S4)
 * Nathan Anderson as Jackson Hyde/Aqualad (S1)
 * Taylor Russell as Koriand'r/Starfire (S2-)
 * Caleel Harris as Vic Stone/Cyborg (S3-S6)
 * Brec Bassinger as Courtney Whitmore/Stargirl (S3)
 * Thomas Barbusca as Roy Harper/Arsenal (S5-)

Antagonists:


 * Anna Diop as Komand'r/Blackfire (S1)
 * David Sobolov as Mongul (S1)
 * Kiernan Shipka as Tara Markov/Terra (S2)
 * Manu Bennett as Slade Wilson/Deathstroke (S2)
 * Chandler Riggs as Jason Todd/Red X (S3)
 * Doctor Arthur Light (S4)
 * The Enlightenment (S4)
 * Joseph Morgan as Sebastian Blood VIII/Brother Blood (S4)
 * Haley Tju as Jinx (S6)
 * The Hive Five (S6)

Invasion!
Airing: November 29-December 1, 2016

Shows: Nightwing, The Flash, & Supergirl

Plot: Wally West investigates a meteor crash outside Central City, which turns out to be a spaceship from which aliens emerge. Jim Gordon tells the team that the aliens are known as the Dominators, and that they had landed on Earth during the 1950s, but mysteriously departed. Wally assembles the original members of the Titans, Nightwing, the new Titans, Supergirl, Hawk, and Dove.

Antagonists: The Dominators

Crisis on Earth-X
Airing: November 27-28, 2017

Shows: Nightwing, The Flash, Supergirl, & Teen Titans

Plot: A Nazi regime rules the parallel world of Earth-88, where the mighty führer Nick Grayson seizes a temporal gateway from the Freedom Fighters, which enables travel to other universes. On Earth-1, Wally West and Linda Park's friends, come to Central City for Wally and Linda's wedding. However, the wedding ceremony is interrupted by invaders from Earth-88 led by Führer Grayson, his Kryptonian wife Kara Zor-El, their hastiest soldier the Flash, and their most decorated soldier known as Deathstroke.

Antagonists: The New Reichsmen

Static
Airing: 2018-21

Seasons: 4

Plot: Virgil Hawkins is a high school student in Dakota City who, as a result of accidental exposure to an experimental mutagen in an event known as the Big Bang, gains the ability to control and manipulate electromagnetism. He uses these powers to become the superhero "Static". Countless others who were also exposed also gained a wide variety of mutations and abilities, many of whom use their abilities in selfish, harmful, and even criminal ways, and Static enters a battle that he finds out is much bigger than he had imagined.

Protagonists:


 * Myles Truitt as Virgil Hawkins/Static
 * Gaten Matarazzo as Richie Foley/Gear
 * Phil LaMarr as Robert Hawkins
 * Corrina Brown as Sharon Hawkins
 * Armani Jackson as Adam Evans/Rubber Band Man (S2-)
 * Cress Williams as Jefferson Pierce/Black Lightning

Antagonists:


 * Jharrel Jerome as Ivan Evans/Ebon (S1)
 * Sean Ryan Fox as Francis Stone/Hotstreak (S1)
 * William Sadler as Simon Stagg (S2)
 * Kel Mitchell as Rex Mason/Metamorpho (S2)

The Outsiders
Airing: December 1-2, 2018

Shows: Teen Titans & Static

Plot: When an alien force attempts a hostile takeover of Earth, it is revealed that the Justice League had, in a show of force, attacked a peaceful planet while under the control of the Dominators two years ago. After the invasion is defeated, those heroes who led the attack leave Earth in an attempt to clear their names. As more and more aliens come to Earth, the people's faith in our heroes begins to dwindle and shift to the Reach, an alien race that offered a peaceful, diplomatic relationship.

Antagonists: The Reach & The Children of Darkseid

Hellblazer
Airing: 2019-22

Seasons: 3

Plot: Demon hunter and master of the occult John Constantine figured there was no longer any point in fighting the good fight since his soul belongs to the netherworld, but when demons target the daughter of one of his closest friends, Liv, he reluctantly rejoins the battle. It turns out that Liv has second sight, an ability to see other worlds and predict supernatural occurrences, a power that makes her a threat to the new evil rising from the shadows. She and Constantine take their combined skills on the road, travelling the country to find demons and send them back to hell.

Protagonists:


 * Matt Ryan as John Constantine
 * Angélica Celaya as Mary "Zed" Martin (S1-S2)
 * Charles Halford as Francis "Chas" Chandler (S1-S2)
 * Harold Perrineau as Manny (S1)
 * Lucy Griffiths as Liv Aberdine (S1)
 * Tala Ashe as Zatanna Zatara (S3)
 * Cozi Zuehlsdorff as Rachel Roth/Raven (S3)

Antagonists:


 * Michael James Shaw as Papa Midnite (S1)
 * Nergal (S2)
 * Klarion the Witch Boy (S3)
 * Trigon (S3)

Apokolips War
Airing: December 8, 2019-January 14, 2020

Shows: Nightwing, The Flash, Supergirl, Teen Titans, & Hellblazer

Plot: Following two failed attempts at conquering Earth, Darkseid and his armies continue conquering other worlds. The Justice League devise a plan to defeat Darkseid by infiltrating Apokolips while leaving the Teen Titans on Earth to defend it. Unbeknownst to them, Darkseid spies on the League through Cyborg. The League are overwhelmed and defeated by Paradooms — genetic hybrid creatures made from Parademons and Doomsday—and a majority of the heroes from both the League and the Titans are killed, while those who survive are placed into Darkseid's slavery. Two years later, the remaining heroes gather in a last ditch effort to find freedom.

Antagonists: Andre Braugher as Darkseid