I’m still at 0/25 for “Masters of the Arena”. Just won a game as monster, still at 0/25. I never played much Arena before Hunt 2.0, but I know I won at least 1 arena game back when it was launched. Now I’m playing the occasional Arena game in Skirmish to try and get the achievement.
Also, I’m at 0/25 for “We’re Not Assassins”. I previously thought this was because the only Rescue games I played was back near launch as part of Evacuation games. Now I think the same thing is happening as with “Masters of the Arena”.
I’ve only ever played Arena as PvP. Most of my Rescue games were PvP with MM; a few were custom games.