Warning! Spoilers ahead for The Book of Boba Fett episode 5.
While the final season of Star Wars Rebels saw B0-Katan Kryze (Katee Sackoff) wielding the legendary Darksaber, Star Wars has officially retconned her claim to the sword of Mandalore, confirming that it was never earned. As Bo-Katan herself revealed in the finale of The Mandalorian season 2, the Darksaber and its ability to unite the clans of Mandalore must be won in combat. However, this was something she never did herself as Mandalore's ruler, leading to some confusion on the part of viewers who had seen both series.
In Star Wars Rebels season 4, «Heroes of Mandalore: Part 2,» the Rebel crew of The Ghost aided the Mandalorian clans against the Imperial occupation of the planet. While the Mandalorian Sabine Wren had procured the Darksaber from the hands of Maul who had taken it from the Death Watch's Pre Vizla, Wren chose to gift the legendary weapon to B0-Katan Kryze, believing she had the strength to rule Mandalore. Bo-Katan reluctantly took the Darksaber from Wren, leading the united clans until the Night of 1000 Tears, otherwise known as the Great Purge of Mandalore at the hands of the Empire, who launched a merciless counterattack that resulted in a near genocide of the Mandalorian people, killing millions.
Related: Why The Mandalorian Isn't With Bo-Katan & The Nite Owls
Once Bo-Katan lost the Darksaber during the Purge, it fell into the hands of Moff Gideon who would carry it through the fall of the Empire until his duel with Din Djarin in The Mandalorian season 2. When Djarin attempted to give the blade to Kryze, however, Bo-Katan stated that the sword must be won in combat. This contradicts Rebels in which she herself had accepted the blade as a gift,
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