In Star Trek: Deep Space Nine, he portrayed the Bajoran scientist Doctor Mora Pol, Odo's guardian scientist in the episodes "The Begotten" and "The Alternate". The Star Trek: Voyager episode "Jetrel" features Sloyan as the title character.
The provided text describes Sloyan's roles as an actor in two different Star Trek series, highlighting his portrayal of Doctor Mora Pol on Deep Space Nine and the protagonist in Voyager's "Jetrel" episode.