Report TOS characters in future ST series in Trek Discussion Posted June 15, 2016 · Edited June 15, 2016 by Randal Shayne Well, I know of a couple... First, we have the three original Klingons- Kor, Koloth and Kang- reprise their roles in Star Trek Deep Space 9: "Blood Oath." Kor would be seen in one or two episodes after this. We also have Mark Lenard, who played both Spock's father, Sarak, and an unnamed Romulan commander in "Balance of Terror". He was seen in Star Trek TNG, in the episode "Unification". I believe it was Part 1.