A mysterious, masked character made his debut in The Walking Dead season 10, episode 16 (the original, delayed finale). This person was teased months ago when AMC released a teaser of the long-delayed finale, but not much was known about them at that time. The trailer revealed a masked warrior wielding two curved, bladed weapons but left his identity a mystery.
After being delayed for months due to the coronavirus pandemic, AMC has finally aired what was originally intended to be the season’s final episode before its six-episode extension. The Walking Dead season 10, episode 16, “A Certain Doom” served as a final chapter in the show’s Whisperer War arc and set the stage for the Commonwealth story in season 11. It also wrote Maggie (Lauren Cohan) back into the show; Maggie hasn’t been around since she left during the time skip that took place in the first half of season 9 (when Andrew Lincoln left the series).
Maggie’s return coincided with the arrival of a new masked character. In the beginning of the episode, this person was seen helping Aaron (Ross Marquand) and Alden (Callan McAuliffe) fight off a group of Whisperers. And later, the character rescued Gabriel (Seth Gilliam) - who was on the verge of death - from the Whisperers. It was revealed in this scene that the masked character is associated with Maggie - or, at least, he came with her from wherever she was. After the Whisperers were defeated, the character never unmasked, thus keeping his identity a secret for the time being. The episode offered no further clues, though their body shape did make it clear that this character is, indeed, male.
Whoever he is, he kept his mask on even when everyone was united and the conflict was over. And what's interesting is that his introduction is similar, in some ways, to Michonne's own introduction when she saved Andrea from walkers in the woods - not to mention the fact that he, too, is wielding a melee weapon. It could be that the reason The Walking Dead is still hiding his face is that he’s a major season 11 character who hasn’t been cast yet. Similar to how Michonne was teased at the end of season 2, what was shown in the season 10 finale may have been a stand-in. His unmasking could be saved for the extra season 10 episodes in 2021.
If Maggie represents the Commonwealth (the same group encountered by Eugene’s group at the end of the episode), then this character could be Mercer, the leader of the Commonwealth’s military and a love interest to Princess in the comics. Mercer’s signature weapons were similar - but not identical - to the ones carried by the masked character in the delayed season 10 finale. Mercer is such an important character in the Commonwealth arc that he's expected to be introduced at some point anyway.
An alternative, but perhaps less likely scenario is that Maggie has no connection to Commonwealth, and that her return happening alongside the Commonwealth’s debut is just a coincidence. If that’s the case, then the masked character may be original to the show. Regardless of which one is the correct answer, the way he effortlessly cut his way through the Whisperers suggests that he’ll be a competent ally in the future. The fact that Maggie trusts him further indicates that he’ll be someone they can depend on in The Walking Dead season 11.