Supergirl: Major Change for SPOILER in Season 6 Premiere

Tonight's Season 6 premiere of Supergirl covered a lot of ground. Not only did the episode pick up the story from the unexpectedly shortened Season 5 and deal with both Lex Luthor and Leviathan, but it also set the stage for the long-running series' final season. That meant some bit shifts for the Superfriends and, for one character, in particular, a big change that may have an impact on every facet of their life going forward.

Warning: Spoilers for Tuesday's season premiere of Supergirl, "Rebirth", below.

The episode largely picked up right where Season 5 left off which meant that Brainy was dying after having bottled Leviathan, Lex Luthor had taken that bottle for his own nefarious plans, and Alex had finally been given her own super-suit, one connected to the weapon J'onn gave her earlier in the season. It's that suit that "Rebirth" built on with Alex getting not just a genuine superhero identity in the episode, but a seat at the table with the rest of the Arrowverse's heroes.

In the episode, the Superfriends managed to fully defeat Leviathan as well as stop Lex, but it came at a price. Lex managed to send Supergirl into the Phantom Zone before he was defeated and because the Phantom Zone projector was damaged, there was no way for the team to know exactly where he sent her. Back at the Tower, Alex is distraught at her sister being missing, but J'onn reminds her that she's as much a hero as Kara is. He gives her her own code name -- Sentinel -- and symbol, both of which once belonged to a Martian colleague of his.

While J'onn tells Alex that the Sentinel name belonged to his Martian friend, there are also some interesting parallels to Alan Scott in the comics. For a time, the original Green Lantern went by the codename Sentinel. While he did not have his ring at that time, he did have powers by way of his glowing hands. While Alex is not a Green Lantern and also doesn't have glowing hands, she does have the ability -- thanks to the Martian weapon J'onn gave her in Season 5, the Hand of the Soldier -- to create any weapon she can think of. It's an ability that can be seen as being similar to creating constructs.

But the changes for Alex go further than just her new heroic role. In the episode, Alex is encouraged to tell Kelly the truth about Kara being Supergirl. It's an overall situation that sees Alex facing a lot of new challenges this season, especially with Kara being lost in the Phantom Zone.

"I think that telling Kelly, you know, Kelly is her person and I think they're able to move forward quickly. In this moment it's really Alex needing her girlfriend and her friends to really support her as she's facing the possibility that she might never get her sister back," co-showrunner Robert Rovner told ComicBook.com. "So it's really, the story is focused on that and her fears, her whole life has been about protecting Kara. You know, that's why she joined the DEO, that's how she got into this was really because she felt this duty to her sister. And for the first time in her life, she's facing that she might have failed at that and so she has to process a lot of things as she's trying to rescue Supergirl from the Phantom Zone."

Supergirl's sixth and final season airs Tuesdays at 9/8c on The CW.

What do you think about Alex finally getting a heroic codename? Let us know in the comments.