Been playing the game and enjoying it barring the odd hard crash, but I'm a bit confused by what counts as a boss creature for this specific achievement. I completed the whole of the campaign and did a bunch of side missions plus 50+ multiplayer wins but I've only had two out of the five boss kills. I didn't even get credit for killing teh very last boss of the campaign - not sure if I was supposed to?
So figured I'd start a new character and try doing the campaign again as maybe some of the earlier bosses gave me credit, but I'm near the end of chapter 4 now and still stuck at 2/5 (40%). So what do I need to kill here to make progress?
I've not fought the Nemesis in Warzone yet, so should that be my next port of call?