2. The Darksaber
The aforementioned and infamous weapon, the darksaber, previously appeared in Star Wars: The Clone Wars and Rebels. Star Wars fans first saw it wielded by Mandalorian warrior Pre Vizsla before it was won by Darth Maul. Then, it came into the possession of Sabine Wren, who learned to use it before passing it off to fellow Mandalorian Bo-Katan Kryze.
Kryze was the assumed current owner of the Darksaber until Gideon emerged with it at the end of The Mandalorian season 1. How Gideon came into its possession is unknown, and it prompts the question about what happened to Kryze and her tribe.
One educated guess about season 2 is that it will explore Gideon’s ownership of the weapon, which likely involves some kind of conflict with Kryze. In a recent interview with People, Giancarlo Esposito confirmed that viewers will see the Darksaber’s “origins” (and also noted that season 3 and 4 are already in the works):
"You will also start to uncover the origins of the Darksaber that Moff Gideon has and how that plays into previous Star Wars history connected to The Clone Wars and other shows. And you’ll start to get a real dramatic sense of the territory."
Until the season gets underway, though, it’s completely a mystery as to when the Darksaber will appear, whether in the present story against Mando (or someone else) or in flashbacks (presumably against Kryze).