I was only listing the two as examples of characters that started off as one-dimensional heavies and developed into much more complex people. Obviously their specific arcs and the circumstances surrounding their creation and development are quite different. Whether it was planned or not is really irrelevant; neither character was really interesting until they were given more depth and nuance than in their first appearance.
(And I still don't understand what "pre
-planning" is supposed to mean when describing the creation of Babylon 5
; "planning" describes it just as well and with more efficiency).
I have to disagree that Crais' motivations changed because the writers had no clear plan for the character. His motivations did change, but logically, as the character developed and we learned more about him. The writers didn't have it all down on paper at the beginning -- thankfully, as Lani Tupu's performance influenced how the character was written, and for the better -- but they didn't push the character around to fit the plot willy-nilly.
(Trying not to have any meaningful spoilers here, since the OP hasn't seen either series).