After a relatively tame start for MMA's lead promotion to open 2018, Saturday's UFC 223 card in Brooklyn, New York, has all the makings to be a must-see and buzzworthy event. 

Adding to the drama, of course, was a massive change to the main event just six days before the fighters enter the Octagon at Barclays Center. But with a pair of exciting title fights atop the marquee and an undercard filled with recognizable names, UFC 223 presents no shortage of bouts that are expected to affect the overall title picture in more than one division. 

Let's take a closer look at the five biggest storylines entering Saturday.

1. Tony Ferguson-Khabib Nurmagomedov is the most cursed fight in the history of curses. Remember the last few months when we all made the same exact joke about how we won't believe this lightweight title bout will actually happen on Saturday until we see both fighters enter the cage of their own volition? What a sick, twisted joke for anyone who stumbled across the headline -- on April Fools' Day, no less -- that Ferguson suffered a freak knee injury that forced this fight to be canceled for the fourth time in just over two years. Make no mistake about it, getting featherweight champion Max Holloway to step in on six days' notice is just about the greatest gift UFC could've received. It also might be the best last-minute fix the promotion has produced, even topping Daniel Cormier-Anderson Silva at UFC 200. But you can't help but be gutted for Ferguson, who waited out Nurmagmedov's medical issues in 2017 to finally secure the defining bout of his career for the undisputed title. 

Can't get enough UFC? Subscribe to my podcast In This Corner with Brian Campbell where we break down everything you need to know in the Octagon.

2. How about the huevos on Max Holloway? Moving up in weight on six days' notice when you weren't already in camp and don't have a fight scheduled is crazy enough. To do so with so much to lose as the current UFC featherweight champion and one of the top pound-for-pound fighters in the world is another thing altogether. But to do all this, and agree to face the unbeaten Nurmagomedov? That's just crazy. Talk about a fighter hungry to make history and become a true crossover star. Should he be victorious, Holloway has a chance to join Conor McGregor -- whom UFC president Dana White said will be stripped of his 155-pound title on Saturday -- as the only fighters in UFC history to hold multiple titles simultaneously. It might also be his only shot at luring McGregor into a big-money rematch. Holloway, who will look for his 13th consecutive win, hasn't lost since he dropped a decision to McGregor in 2013 when he was just 21. 

3. Immediate rematch gives Joanna Jedrzejczyk a chance to redeem legacy. One win away from tying Ronda Rousey's UFC record for title defenses by a female and seemingly on the verge of stardom, Jedrzejczyk saw her strawweight reign come violently undone via first-round TKO against Rose Namajunas. While the proud Polish fighter wasn't looking for sympathy when she spoke of how extreme her weight cut was ahead of the fight (included having to lose 14 pounds in the final 15 hours), she maintains it played a big role. After shaking up her team ahead of the rematch, Jedrzejczyk gets the rare chance to repair her legacy in one fight -- a la Georges St-Pierre in his 2008 rematch with Matt Serra -- should she win dominantly. 

4. Have we seen enough to admit Anthony Pettis will never be the same? Outside of former bantamweight king Renan Barao, it would be hard to find a UFC champion at the peak of his prime take such a hard fall after a single loss. After winning the lightweight title from former WEC rival Benson Henderson in 2013, Pettis saw his face adorned on the cover of Wheaties cereal boxes. But a devastating three-fight losing skid soon followed. Since then, Pettis' attempts to right the ship has seen him alternate wins and losses over his last four. In total, the 31-year-old Pettis has lost five of his last seven entering Saturday's bout against Michael Chiesa, where a loss would remove any remaining hope that a title run (or even a winning streak) might be in his future. 

5. Felice Herrig enters her moment of truth. An MMA veteran since 2009, Herrig didn't make her UFC debut until "The Ultimate Fighter" women's strawweight season of 2014. But despite being known for her good looks and equally flashy attire and skill set, Herrig wasn't quite taken seriously as a future title contender. Somewhere along the way, Herrig made a recommitment to the fundamentals of the sport and now has a four-fight win streak to show for it. At 33, Herrig has set her focus exclusively on gaining a title shot and believes she could be in line for one with a win on Saturday. Getting there will be no easy task, however, as Herrig faces the toughest challenge of her career on paper against former title challenger Karolina Kowalkiewicz. This is where we find out exactly what Herrig is made of.