Batwoman Finale Proves We Need a World’s Finest Crossover with Supergirl Next Season

The penultimate Season 1 episode of Batwoman, "A Secret Kept from All the Rest" Alice (Rachel Skarsten) made a major discovery: the only thing that can pierce the armor of Batwoman's suit and thus kill her is Kryptonite. Sunday's season finale "O, Mouse!" saw Alice go to extraordinary lengths to procure that while Kate Kane/Batwoman (Ruby Rose) processed the realization that green rock that she's been holding onto as a failsafe against Supergirl -- with the Kryptonian's blessing -- since "Crisis on Infinite Earths is dangerous to her as well. It's a strange situation and it's one that proves what the Arrowverse needs next season is a World's Finest crossover featuring Batwoman and Supergirl.

Warning: Spoilers for tonight's Season 1 finale of Batwoman and Season 5 finale of Supergirl below.

Once it's clear that Alice knows that Kryptonite is the only thing that can pierce Batwoman's suit and kill her, Luke Fox (Camrus Johnson) sets to work trying to destroy the piece of Kryptonite that Bruce Wayne kept in the cave, a shard given to him by "a friend" -- Superman -- to hold onto just in case. The logic is that if Luke can destroy that piece of Kryptonite, Batwoman will be safe as it's the only one. He's ultimately successful after a suggestion from Mary (Nicole Kang) but he soon learns what fans have known for a while: there's more than just that one piece of Kryptonite. Kate has her own piece, given to her by the Bruce Wayne from a now-destroyed world in the Multiverse and left in her care by her own super friend -- Supergirl. Despite knowing that it can kill her, Kate refuses to destroy the piece. It's not hers to do so.

With Kryptonite now being in play as a threat for Batwoman just as it is for Supergirl on her show, it's a perfect set up for a World's Finest crossover to bring those two heroes together again, especially since the threat Kryptonite presents has been a big deal for Supergirl recently as well. That show's Season 5 finale, "Immortal Kombat" saw Leviathan use all of the Kryptonite it could gather against Supergirl, though they were ultimately unsuccessful. With both heroes threatened by the rock, it would make sense to see them come together to try to stop Alice should she get her hands on the Kryptonite -- something that feels more possible than ever now that she's given Tommy Elliot Bruce Wayne's face.

A "World's Finest" crossover between Batwoman and Supergirl is something that Batwoman showrunner Caroline Dries has been clear that she would like to see happen in Batwoman's second season. Dries recently told ComicBook.com that she hopes to further develop the Kara/Kate friendship once production resumes.

"In season two, I hope we just get back up production, and everything is normal, or at a normal amount at some point. Because you know how the crossovers are just so hard to schedule and blah blah blah, and I'm sure COVID isn't going to do us any favors in that regard," Dries explained. "But to me, the most important relationship is Batwoman and Supergirl. So, I think if we are able to do any crossover, that would be what I would try to focus on."

In fact, the idea that Kryptonite could be a real threat to Batwoman came from the Kara/Kate relationship in "Crisis on Infinite Earths".

"That idea came from me feeling like -- I just didn't want the next weapon we talk about to be something that was manmade, that if somebody put their heads together, they could maybe go into a lab and cook up. So, what exists in the world that is unique enough, that there'd be a very limited amount that makes it special?" Dries revealed to us. "The idea of Kryptonite popped in my brain, and it made perfect sense to me, that this sort of talisman exchange between Kara and Kate in the crossover was just so much more than just a rock. It, to me, represents their bond and their friendship and that sense of trust between them. And I kind of like anchoring the chaos of all of the Arrowverse and all of what happened in "Crisis" to this friendship."

It seems like The CW is looking at doing some form of "World's Finest" type crossover next season with Batwoman, though it won't necessarily directly be with Supergirl the way fans and Dries hopes. During the network's schedule reveal on Thursday -- which revealed that Supergirl won't return until mid-season 2021 -- network president Mark Pedowitz revealed that there will still be an Arrowverse crossover, but instead of a multi-night event, it will be a much smaller, two-hour event featuring Batwoman and Superman & Lois -- with other characters appearing as well.

"We're still working on it, but it'll be a much smaller event," Pedowitz said. "We're talking about a two-hour event, with Superman and Batwoman, with characters coming in from our other shows."

What do you think? Do you want a Batwoman/Supergirl World's Finest crossover next season? Let us know your thoughts in the comments below.