How long does Borderlands Bloodlust last?
It lasts until someone else caps 3 ruins on the same map, or the matchup ends.
On the map where you have the bloodlust, the UI in the top right will say “Your realm has earned Borderlands Bloodlust” (or something like that) instead of “X colour has Borderlands Bloodlust….” Other than that, there’s no way to tell, so you’d have to map hop to check them. 90% of the time it’ll be your home border though.
Or reset on Fridays.