Undersea Abomination - Tak Rethan Abyss ( T8, Havoc DH ) Brann aggro broken?

Easy boss but I want to highlight how I barely did any damage for 30 seconds and Brann still didn't manage to pull aggro. What's up with that?

[@gymlife408]

There needs to be some kind of boss guide for these like they have in dungeons

[@gymlife408]

There are only two videos even mentioning this on all of youtube