Let's count all of the hidden references to classic Samurai Jack
This episode had quite a few, and they're all worth revisiting, since they came from both old episodes as well as riffs on other heroic tales from pop culture and history:
The Three (Formerly Blind) Archers -- These are the archers Ashi ran into. They were blinded and imprisoned as the guardians of a time portal, and Jack had to defeat them in a mostly dialogue-free, much-beloved early episode "Jack and the Three Blind Archers." At the end of that episode, they regained their sight.
The Woolies -- Another Season 1 callback, the Woolies are a sentient race who were subjugated and set to perform hard labor by the Chritchellites. Jack saved their butts in "Jack, the Woolies, and the Chritchellites."
Olivia and the Ravers -- She's the DJ at the rave Ashi discovers, and Jack saved her as a small child from a mind-controlling DJ in the episode "Jack and the Rave." Ashi's dance in this episode also echoed Jack's dance from the original episode.
Da Samurai -- He was an aspiring, and funkier, samurai that Jack met in his travels, when he completely embarrassed Da Samurai in "Samurai versus Samurai." Keegan-Michael Key voiced him in this episode.