For this one you need to complete every single survival missions with at least 1,500,000 karma on the counter. This is hard, but no impossible, don't lose your focus though.
And always try to keep your karma multiplier 5x, just because you won't have to earn as much karma then. AND more important is, when you have completed the waves of enemies for the first time, the difficulty will go up from Acolyte - Warrior - Mentor - Master Ninja, and you don't want that.
Good luck!