You may be looking for:
Marine master sergeant
Master Sergeant Sousa is a neurally resocialized marine master sergeant in the Dominion Armed Forces. The resoc left him perpetually "chipper". His status was theoretically secret, but it was well-known to troops in his command.
In February 2504, Commander Rindge assigned Sousa the task of interrupting White's upcoming R&R. A rebel group calling itself the Players' Club was attacking Kel-Morian miners at the moon of Chanuk. The group had caused trouble for the Dominion in the past, so the Dominion took the opportunity to attack them there.
Sousa's command fought the Players' Club in the mining tunnels of Chanuk. He ordered White into combat. White was thrown into an elevator which was damaged by a grenade while White was in it. Meanwhile the Dominion decided to pull out of the situation, abandoning the miners. When White regained consciousness, Sousa, who had remained behind, reassured him they would free him, then helped him out of the elevator and to the infirmary. Along the trip, Sousa chatted happily about the defeat of the Players' Club at the hands of the Dominion.