Fives and AZI-3
*Beware Clone Wars Spoilers below*
Ya know honestly I think the reason Fives bonds so well with AZI-3 in season 6 is because he kind of reminds Fives of Echo. AZI-3 is all about following orders and is indignant when Fives suggests breaking the rules (“But we’d be disobeying direct orders!” / “Yup. For the second time today”.) but ultimately is Fives’ ride or die for the duration of the arc.
And when you think about it, Fives would be so lost without AZI-3, just like he was lost without Echo.
And. AND. When Fives regained consciousness after Nala Se drugged him, who’s the first character he asked about? AZI-3.
I think it was meant to parallel a relationship Fives and Echo could have had, but we never got to see. By giving us AZI-3, we were able to see that part of the iconic duo we never really saw in TCW, and I think that was a very clever and creative way to give us one last salute to Echo and Fives, by letting AZI-3 literally echo Echo.