High Class Killer
Is there some specific requirement for this challenge? It says get kills with 4 of the unlockable personas(Blacksmith, Theif, Footpad and Mercinary) which i've done but it didn't get completed.
What am i missing here?
I remember getting it, but most of the stuff I get are on accident. I think you should just keep selecting each unlockable for every match and keep trying. Maybe there's a detail in the description you're missing?
Brotherhood's unlock system seems very buggy to me. For example: I wanted to unlock a different form of templar vision, and it told me to complete a challenge. I looked through all my challenges, didn't find the one i was looking for.
I remember getting it, but most of the stuff I get are on accident. I think you should just keep selecting each unlockable for every match and keep trying. Maybe there's a detail in the description you're missing?
That's what i thought but it just says "Get Kills with 4 of the unlockable personas". If there's a more specific requirement then it doesn't say that in the game.
The unlocked ability was probably a level 3 challenge, you just get exp for the first two levels of the challenge so you dont know which one it is
I don't know about the "High Class Killer", but I guess there's nothing for it but to keep trying. Jack is right about the other challenges though, they all work with a 3-part system.
*Random Challenge*
part 1 / 3 - Do this 10 times (0/10) _ Reward: Experience
part 2 / 3 - Do this 40 times (10/40) _ Reward: Experience
part 3 / 3 - Do this 100 times (40/100) _ Reward: Evolved Ability/Experience
I hope its sort of clear that the counter is always cumulative with the last completed step, the total count of doing 'this' here would be 100, not 10+40+100=150. At least, I believe this is the case. If it isn't, somebody please correct me quickly and I'll edit this. Don't want to be posting wrong information 
.