As the 2021 calendar winds down, WWE returns to one of their big traditional events when they hold Survivor Series on Nov. 21 in Brooklyn. Survivor Series is the second oldest annual WWE pay-per-view, behind only WrestleMania.

In the main event, universal champion Roman Reigns will represent SmackDown when he takes on WWE champion Big E from Raw. On the women's side, SmackDown champion Charlotte Flair will take on Raw champion Becky Lynch. Add to that a pair of five-on-five matches in Survivor Series tradition and there's a stacked event planned, even without any championship stakes.

While there aren't really storylines beyond brand vs. brand, the novelty of brand crossover matches is such that the event maintains a high level of intrigue.

Let's take a look at what we know -- and what we expect -- at WWE Survivor Series.

WWE Survivor Series matches

WWE champion Big E vs. Universal champion Roman Reigns: Big E won the WWE championship on Oct. 13, cashing in his Money in the Bank contract on Raw and beating Bobby Lashley. He has since mixed it up with Reigns a few times, once in six-man tag action with his New Day teammates against The Bloodline and once in triple threat action with Lashley also in the mix. Reigns has been universal champion for more than a year, dominating all comers. Reigns has been battling Big E's New Day teammate and current King of the Ring, Xavier Woods, on recent episodes of SmackDown.

SmackDown women's champion Charlotte Flair vs. Raw women's champion Becky Lynch: Flair and Lynch have a long and storied history both as teammates and opponents. They have shared the ring more than 45 times on TV and PPV and more than 200 times when live events are factored into the equation.

Team Raw (Seth Rollins, Finn Balor, Kevin Owens, Austin Theory, Bobby Lashley) vs. Team SmackDown (Drew McIntyre, Xavier Woods, Jeff Hardy, Happy Corbin, Sheamus): The traditional Survivor Series match for the men's side has seen some small changes. First, on the Raw side, Lashley dominated Dominick Mysterio to win Mysterio's spot on the team. Lashley then beat Rey Mysterio and Adam Pearce removed the elder Mysterio from the team and replaced him with Austin Theory. On SmackDown, Hardy battled Sami Zayn, with the loser (Zayn) being removed from the team. Sheamus secured the final spot by winning a fatal four-way on SmackDown..

Team Raw (Bianca Belair, Rhea Ripley, Liv Morgan, Carmella, Zelina Vega) vs. Team SmackDown (Sasha Banks, Shotzi, Shayna Baszler, Natalya, Toni Storm): On the women's side of things, the teams have remained relatively stable with the exception of Team SmackDown, which lost brand newcomer Aliyah after she drew the wrath of WWE official Sonya Deville for helping Naomi in a six-woman tag match. Deville removed Aliyah from the match but Toni Storm was named as replacement.

Intercontinental champion Shinsuke Nakamura vs. United States champion Damian Priest: Nakamura's championship reign has been a bit forgotten, but Priest has been getting a character refresh on Raw. In recent weeks, Priest has shown a new aggressive edge, showing new levels of violence and being less of the "fun-loving character" he was at WrestleMania when he teamed with music superstar Bad Bunny.

Raw tag team champions RK-Bro vs. SmackDown tag team champions The Usos: The Usos and Reigns have dominated SmackDown while Randy Orton and Riddle have made for a great odd couple team on the Raw side. The two teams are in need of fresh opponents, which is exactly what they'll get at Survivor Series. They also had a big run-in on Raw, battling as part of a six-man tag match as RK-Bro teamed with Big E and The Usos teamed with Seth Rollins.

25-man battle royal: Announced two days before the event, there will be a 25-man cross-brand battle royal on the card. Some big names, including Omos, Cesaro, Sami Zayn, The Street Profits and Alpha Academy are set to be a part of the match.