Superhero Insider: Crisis on Earth-X brings out the best in the Arrowverse

Each week, we break down the biggest moments from Supergirl, The Flash, DC's Legends of Tomorrow, and Arrow — both here on EW.com and on SiriusXM's EW Live every Friday during Superhero Insider.

This week's fresh batch of episodes brought together the heroes of Supergirl, Arrow, The Flash, and DC's Legends of Tomorrow for the annual four-way crossover, this year titled Crisis on Earth-X. The villains of Earth-X — where the Nazis won WWII — crashed Barry and Iris' wedding in a bid to gain Supergirl's heart. Literally, not romantically. They needed it to fix their over-radiated general, Overgirl. How did their master plan fare? Here are the highlights:

SUPERGIRL

Though heartfelt moments like Joe's speech, the arrival of a mystery character clearly connected to Barry and Iris, and Kara singing at the nuptials were marred by the arrival of Nazis, the first hour of the crossover kicked off what turned into an emotional and hilarious journey for Alex and Sara. After the Supergirl and Legends heroines shared a drunken night of passion, Alex's awkwardness gave way to actual fears as to whether she made the right decision with Maggie, culminating in both characters being able to help each other and get a bit of closure throughout the course of four episodes. Despite not being at the forefront, it was a surprisingly strong and compelling storyline that took viewers on a complete journey. —Natalie Abrams

ARROW

Instead of there being a Dark Flash from Earth-X, Tom Cavanagh suited back up as Reverse-Flash, like the Reverse-Flash who killed Barry's mother and formed the Legion of Doom. This time, he's one third of the Dark Trinity of villains to face our Holy Trinity of heroes. You may be asking yourself: Whaaaaaaaaat? Yeah, Eobard Thawne has died so many times that it's unclear exactly how he's still alive or from which era Barry's greatest nemesis hails. Regardless, it was still a nice treat to see Cavanagh back in the yellow suit. And a good nod to the comics — and there were so many throughout the four hours, including Red Son and All-Star Superman! — that Barry can't seem to ever truly get rid of Reverse-Flash. Plus: Reverse-Flash noted that he, at some point, tussled with Superman, which could (maybe, possibly) explain how Oliver somehow acquired Kryptonite to make an arrow on Earth-1, but hopefully that's a Crisis for another day. —N.A.

THE FLASH

One of the things I absolutely loved about this year's epic crossover was how many great pairings we got. In addition to Sara and Alex, we also got a chance to see Felicity and Iris spend some time (read: kick some ass) together. When Reverse Flash, Overgirl, and Dark Archer take over S.T.A.R. Labs, it's up to Felicity and Iris to save the day, reinforcing the idea that you don't need powers or a colorful leather outfits to be a hero. Given recent behind-the-scenes drama on in both the Arrowverse and Hollywood in general, there was nothing better than seeing Felicity and Iris, both of whom usually hold down the fort while the masks have all the fun, get the drop on two Nazis soldiers. Moreover, The Flash portion of the crossover, which mainly took place on the Man in the High Castle world of Earth-X also introduced my new favorite couple, The Ray (guest star Russell Torvey) and Citizen Cold (Wentworth Miller), a.k.a. Leonard Snart's Earth-X doppelganger.—Chancellor Agard

DC'S LEGENDS OF TOMORROW

The standout moment from the crossover's finale was, of course, the upsetting death of Martin Stein. Honestly, I think my colleague Shirley Li perfectly summed up my reaction to that moment in her recap: "NooooooooooooooooooooooOOOOOOooooooooooooooo…" (I paraphrased) Yes, we all knew this moment was coming at some point down the line, but that didn't make any less heartbreaking, especially because Stein went out as a hero, sacrificing his life so Jax, his other half/surrogate son, could live. Jax will never forget that sacrifice, and neither will we. —C.A.

This Week's Crossover Moments

• Literally everything.

Listen to Superhero Insider

Click below to listen to this week's Superhero Insider, which airs every Friday at 10 a.m. PT/1 p.m. ET on SiriusXM's Ch. 105, hosted by Kyle Anderson and Natalie Abrams. <iframe width="100%" height="300" scrolling="no" frameborder="0" src="https://w.soundcloud.com/player/?url=https%3A//api.soundcloud.com/tracks/363611309&amp;color=%23ff5500&amp;auto_play=false&amp;hide_related=false&amp;show_comments=true&amp;show_user=true&amp;show_reposts=false&amp;show_teaser=true&amp;visual=true" class="" allowfullscreen="" resize="0" replace_attributes="1" name=""></iframe>

Supergirl airs Mondays at 8 p.m. ET, The Flash airs Tuesdays at 8 p.m. ET, followed by DC's Legends of Tomorrow at 9 p.m. ET., and Arrow airs Thursdays at 9 p.m. ET on The CW.