I felt a bit strange this season, getting this achievement.
I have never done any of the "Conquest" achievements without doing a buttload of arena games or RBGs, and this season I was really lazy. The Gladiator's Sanctum gave me a decent amount of conquest, as did Ashran.
But, I must have done more arenas than I thought because I did manage to do my 100 Arena games for the mount back in February and get my Rainbow Raptor.
And also the Coliseum threw in a fair amount of Conquest too. But I've only done it once.
And it's been a crappy season for me. I haven't been trying very hard to arena, and I haven't enjoyed doing a double caster arena. I have really liked a melee/caster comp (though I wonder what a double melee comp would have been like).
I did a couple of games as Boomy but it's not really my thing so I didn't enjoy it. I don't mind so much being Boomy for battlegrounds though, but I still think I do best in games where I'm healing.
The achievement itself is quite easy to do if you cap every week. You don't even need to do extra cap, like get rating in RBGs or Arenas. It makes me wonder if they should make it a little harder just to show you put in the extra yards for the achievement. If that had been the case maybe I would have put in some extra yards for it.
That still leaves Sev without his 100 games. His ambivalence about playing doesn't help me get motivated, and the lack of a willing melee DPS (especially a DK coz I love DK afflock) makes it a difficult also. We did try a few pugs a few weeks ago - one paladin was decent but terribly condescending - it started out with him telling Sev to play demo and berating me for not healing him when he was next to me. Got rid of him. Then we did a carry arena which won a few games but mostly were losses. Anyway, I will hopefully feel a bit more motivated next after this holiday!