This is me 100% making shit up:

Koltira is technically Tev’s commanding officer. (Or at least he was until he went missing and Tev apparently gets promoted above him next expac.) He’s also kind of like Tev’s disapproving mother-in-law. The dude pretty much complains loudly about everything Tev does, though his actions don’t really back up his disapproval at all.

Absolutely none of this prevents Tev from talking about “Deathweaver’s human boyfriend.” until Kolitra’s ears wilt and he orders Tevruden to shut up. So I’d say their interactions are mutually antagonistic. Which is actually probably a pretty positive relationship when you’re a DK.

Thassarian he is a bit more neutral on; yeah he went to the Alliance, (alliance vs horde is a whole other post) and there was that whole incident w/ Kolitra in Andorhal, but Tev feels that death knights are Ebon Blade first and members of their respective factions second.