Somehow by the end of the night I did get the achievement check mark. Not sure when because I thought I had checked the achievement window every time we killed another and never saw it happen. Others in group also werent getting the check but eventually did.
Captain of the Guard is the PH for Master of the Guard, which is the Trigger mob for the Overseer Reborn. When I was there, CotG was uncommonly dropping spells, but nothing else.
So... he's got rare HP. He's in the rare list. But here's how it works right now... - The Captain of the Guard rare in the ach list is updated by killing The Overseer Reborn. - The Overseer Reborn rare in the ach list is updated by killing Ulessa the Insane. (Not in the rare list right now). And as mentioned, The Captain of the Guard has rare level HP (212M HP), gives a spell sometimes if he's the yellow con version only.