In this slowdown period I have been hitting Ashran as often as I could, and I remember lamenting not having done it before the 6.2 changes, but when they announced that long wait till Legion I figured I had plenty of time to get it done.
So, just after Christmas, I got it done! I looked at the dates that I completed each Nemesis, and it was rather interesting...
I did Night Elf first, and finished that on Valentine's Day.
Then I had a bit of a break from Ashran and got Draenei done on 21 May.
I must have been working pretty hard after that because I got my Dwarves on 30 May. I remember complaining to Crooked about Dwarves not coming out after dark, but since I managed to do it in 9 days I must have had a good run with buddies in my group doing the same Nemesis.
Gnomes were completed 2 weeks after on June 12. I might have had some help with that I think (as in someone made a gnome killing group and I joined in).
Pandas was my "cheating" one, and that was done on 23 August.
Worgen did take me a while, I finished that on Boxing Day.
I had left human till last because I figured it was the easiest one to do, and I was right. Taxar was kind enough to let me kill his human character so I could get my one heart instead of waiting in the 20 minute Ashran queue to get one heart and then jump back out again to hand it in before I came back for another 20 minute queue. There were a few people on humans, so I actually managed to knock of humans in an hour. Someone told me they did it in 20 minutes, but I'm just a healer, not a killing machine.
And so now I am a Warlord of Draenor. COOOOOL.