S3E20 'Through the Looking Glass' involves Miles "Smiley" O'Brien from the "evil universe" previously featured in S2E23's 'Crossover' breaking into the main universe and kidnapping Commander Sisko. Apparently, "evil" Ben is the leader of the Terran resistance (which also features other Federation races like the Vulcans) against the Alliance of the Cardassians, Klingons, and Bajorans. Apparently, Ben got himself killed trying to convince Jennifer, his very much alive and estranged wife, to quit developing a new sensor array for the Alliance that would collapse the resistance in a instant. Smiley kidnaps our Sisko to complete the mission that "evil" Ben couldn't.
Tuvok of the Voyager series is present and vocal as a member of Ben's resistance. I had to look it up, and the Voyager series was just then getting started.
Without too many details (or spoilers), Ben manages to convince Jennifer to leave the Alliance. She knows, however, that this isn't the Ben she married; maybe because while he has the swagger he doesn't possess the same id or egocentric worldview. And then Smiley sends him home.
I'm sure it violates some variant or subparagraph of the Prime Directive, but he should have "hit that" one more time before going home. I mean, it's his wife that he hasn't seen in over 4 years in his universe. And it didn't seem like she wouldn't have been receptive to this version of Sisko. There has to be a "but she's my dead spouse and willing even though she knows I'm not from her timeline" exception clause. And even if there's not, Sisko already broke the rules by interfering to rescue Jennifer in the first place. In for a penny, in for a pound, they say. And Jennifer Sisko didn't seem like she would have minded giving him change.
 For those of you without the DS9 scorecard, Jennifer died before Sisko took command of Deep Space Nine (aka Terok Nor). She died when the USS Saratoga was attacked by the Borg at the Battle of Wolf 359 before the series started.
 He isn't given a name, but the voice and mannerisms are very much Tuvok. I don't know if this is official canon but I'm going with it.
 Oh, bad pun. I'm sorry.