Had he been cast in a different role as an out-and-out villain, rather than a misguided and unbalanced genius, there is no doubt that he could have been one of the crew's most dangerous and fondly-remembered adversaries, if written intelligently. The constraints of the Daystrom role meant he played him as a man driven to madness by a lack of recognition for his inventions, distracted and tormented by his desire to see M-5 become his greatest contribution to mankind. But imagine him in a role that let him be in charge of his capacities, pitted against Kirk as one of the few enemies that could match him in sheer force of will. What a Klingon captain he would have made! Even Kang would have respected him as a force to be reckoned with.
We see some of that quality in his thoroughly charming, yet chilling performance as Mumwalde, the so-called "Blacula" of the two films he played the character in. His alternately threatening-yet-sensitive approach to the role, portraying him as a victim as well as a predator, lifted it above the low-budget exploitation film genre it was a part of at the time.
This time we look at an article from the April/May 1990 edition of the Official Fan Club Magazine (see the cover). These two pages featuring Marshall were part of a series of articles that focused on guest stars from the show. The cover feature on Nichelle Nichols is scanned and ready to post in a future entry.
Below, some screen captures from the episode (source: Trekcore.com) that illustrate Marshalls' height over the series stars.

"So, what do you think of my profile, Doctor?"

Kirk punctuates his criticism of Daystrom with a swift jab to the ribs.

The captain takes out his frustration on Daystrom's jumpsuit and chest hairs.

Shatner was undoubtably standing on a box for this scene.
Below, a publicity still and poster from Marshall's other role he is best known for: "Blacula." I have both films in my DVD collection, and enjoy watching them when I'm in a 70's kind of mood.
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"It's close to midnight and something evil's lurking in the dark..."















































