The Darksaber; legendary Star Wars weapon of Mandalore, with its black energy blade and crackling white edge, is both an ancient lightsaber and a powerful symbol of leadership to this race of warriors. Forged over 1,000 years before the events of Star Wars by Tarre Vizsla, who was both Mandalorian and Jedi, it is said that whoever wields it can lead all of Mandalore.
After Din Djarin (Pedro Pascal), defeated Moff Gideon (Giancarlo Esposito) with his Beskar spear and claimed the light saber, he offered it to Bo Katan (Katee Sackhoff) - the aspiring leader from Clone Wars and Rebels - who refused to accept the blade, as it may not be given, but by creed may only be wielded by those who have won it in battle.
Now the lone Mandalorian carries the Darksaber into his bounty hunting adventures, as he seeks out his place among these warriors, hoping to one day be reunited with the Jedi child and Mando clan foundling, Grogu.
This is the way.