“Yeah we didn't kill each other. So I guess we're friends now.”
―Zeb considering Kallus as his friend[src]
The relationship between former ISB turned rebel agent Alexsandr Kallus and Lasat Warrior Garazeb Orrelioshas varied from the show, first starting them off as rivals before becoming close friends and brothers in arms.
Since the beginning, theyhad an animosity and mutual hatred for each other since they first met up until the events of "The Honorable Ones," where they gained a better understanding of each other. Zeb once offered Kallus to join the rebellion, promising him that they will make Kallus feel welcomed. However, he declined and decided to stay with the Empire. To make up for what Zeb did, Kallus grew disillusioned with the Empire and became Fulcrum. As of "An Inside Man," when Zeb learned his old foe was Fulcrum, he realized he accidentally recruited Kallus and considers him his friend.
After the war, Kallus and Zeb retired to Lira San, this time as friends.