Out of all the actors we want to see again, Jeffrey Combs is at the top of the list. That name might not ring a bell right away, but Combs has played an array of characters in the Star Trek world, including some of its best villains. In Deep Space Nine, he played Weyoun, a political overseer from the Dominion who had a creepy, slimy personality. During the show's run, Combs ended up playing multiple different characters, each with a different personality.
He also appeared in Voyager and Enterprise. In the latter, he played Andorian commander Thy'lek Shran—one of the best villains in Star Trek canon. Combs is extremely talented, and able to portray radically different characters so well that most people don't even realize that Shran and Weyoun are played by the same actor.
Combs would fit perfectly into Discovery. He specializes in playing creepy villains, which is something the show will need, and he's an actor that can fill out other roles as necessary. Having him in the cast would also give fans something to look forward to and help fight any anxiety they feel as the new series comes closer. In fact, let's just have Jeffrey Combs play every role in Discovery. What could go wrong?