The Best Episodes Written By Todd Helbing

The Kents fight with everything they have as Luthor makes his final move on Smallville.

Reeling from failure, Jordan begins to spiral; Jonathan discovers newfound strength.

Luthor plans to move LuthorCorp to Smallville, but finds opposition in Lana.

Luthor challenges Lois to a live telecast debate, though not everything is as it seems; John Henry and Clark face a troubling possibility.

Barry and Team Flash come up with a plan to stop Cicada. However, the plan calls for Barry and Nora to travel back in time to gather some key necessities. However, Barry hesitates, concerned about his daughter seeing certain parts of his life. Meanwhile, Sherloque takes his concerns about Nora to Iris, and Caitlin turns up a key asset in the fight against Cicada.

Mark Mardon, having survived his apparent death during the black-matter explosion, returns seeking revenge on Joe for the death of his brother Clyde... and has the same weather-manipulation powers as his deceased sibling.

When a nuclear bomb detonates in downtown Central City, Barry, Jesse Quick and Jay Garrick slow down time by entering Flashtime. As everyone in the city is frozen, the three speedsters push themselves to the breaking point to save the city and everyone in it.

Superman's worst nightmare comes to life and Lois confronts Leslie Larr. Meanwhile, Lana, Kyle and Sarah agree to stay to help General Lane.

In an ironic twist of fate, a gladiator from the house of Batiatus will stand in the way of Spartacus trying to free Crixus from Roman captivity. Ilithyia's scheming puts her marriage to Glaber at risk.

Barry enjoys the annual tradition of tree trimming and gift exchange with Joe and Iris. He gives Iris a touching gift, but the moment is interrupted by Eddie’s arrival.

When Harrison activates the particle accelerator, the team has no choice but to evacuate the five metahuman prisoners. Unfortunately, with time running out, Barry has no choice but to turn to Captain Cold for help. Meanwhile, Eddie escapes but has some surprising news for Iris.

As Smallville celebrates its first Harvest Festival since Martha’s passing, Clark is reminded what his mother meant to him and learns a lesson that will help him move past her death. Meanwhile, Lois makes a breakthrough in the investigation of Morgan Edge. Lastly, Kyle tries to reconnect with Lana, but it seems like he might be falling back into his old ways.

Beautiful, athletic, and trained as highly skilled assassins, Kitana and Mileena have grown up thinking that they are sisters. Shao Kahn, Emperor of the Outworld, has tricked Shang Tsung into becoming his servant for Mortal Kombat by making him clone Mileena as a Tarkatan clone of Kitana, out of Shao Kahn's fear that Kitana wouldn't love him enough if she ever found out the truth about her Mother and Father.

The rivalry between Kitana and Mileena grows, while Kitana attempts to learn the truth behind her childhood and the real identity of her parents.

Vandal Savage arrives in Central City and sets his sights on Kendra Saunders. After Vandal attacks Kendra and Cisco, they turn to Barry for help. Realizing how dangerous Vandal is, Barry takes Kendra to Star City and asks Oliver and team to hide her until he can figure out how to stop Vandal. However, things quickly go from bad to worse when a man with wings AKA Hawkman shows up and flies off with Kendra. Meanwhile, Harrison develops a serum to make Barry run faster and asks Jay to test it out. The crossover continues on Arrow S04E08 Legends of Yesterday (II).

When Lt. Sonya Blade calls in a report that she has tracked down Kano, "Jax" Briggs convinces his superior, Kurtis Stryker, to take in a squad of men, only to discover that it's a trap.

Superman is in a brutal battle with Luthor's monster; Lois and the boys race to save General Lane.

When aliens called the Dominators attack Central City, Barry speeds over to Star City to ask the Green Arrow for help in stopping them. Realizing the battle against the Dominators is bigger than they thought, they track down the Legends of Tomorrow, and Barry and Cisco create a breach to bring back a secret weapon – Supergirl. Once all of the super friends are assembled, they come up with a plan to attack but a shocking secret related to Flashpoint is revealed and suddenly no one is sure who they can trust. Meanwhile, Wally wants to join the battle against the aliens but Iris tells him he’s not ready. The crossover starts on Supergirl S02E08 Medusa (I). It continues on Arrow S05E08 Invasion! (III) and DC's Legends of Tomorrow S02E07 Invasion! (IV).

Barry faces off with his oldest, and most formidable nemesis, Reverse Flash.

While adjusting to their new lives in Smallville, Lois and Clark make an important decision concerning one of their sons. Meanwhile, tensions begin to rise between Lois and Morgan Edge. Lastly, Lana Lang Cushing invites the Kent family over for a barbecue.

Batiatus purchases a fresh batch of slaves during an auction to be trained as gladiators and ponders the idea of selling Crixus.

Superman and Lois' return to idyllic Smallville is set to be upended by mysterious strangers.

On Earth-2, the team races to find Zoom's lair and asks for help from the most unexpected source. Meanwhile, back on Earth-1, Caitlin rushes to perfect Velocity-9 so that Jay can stop the Geomancer.

Pete Ross returns to town and finds a number of surprising changes since his departure. Besides resolving his feelings toward Clark since he learned of his friend's secret, Pete has to deal with the acquisition of a superpower of his own.

After the shocking revelation that Zoom is Jay Garrick, Barry is more determined than ever to get back to Earth-2 to stop Zoom forever. Desperate to find a way to increase his speed, Barry decides to travel back in time and masquerade as his earlier self in order to get his arch-nemesis, Dr. Harrison Wells/Eobard Thawne, to teach him how to run faster. However, things don’t go as planned and Barry is stunned to face familiar foe Hartley Rathaway, as well as old friend Eddie Thawne. Iris makes peace with her past in order to embrace her future.