Title. Have done it four times now and I didn’t get it. I have seen people with the illusion, so it has to work, but am I doing something wrong? Do I have to kill the boss with the riposte attack? Wouldn’t bother me that much if a) the illusion was not behind the challenge and b) the challenge wasn’t so damn annoying and random to set up. I can definitely confirm that I did not get hit, by anything, neither the boss nor anything else.
You have to block a monster’s attacks with the charged heavy (as in, block by charging a heavy with the bretonnian longsword and holding it there) 3 times, and then get the killing blow on the monster, without ever taking damage from the moment the monster spawned.
Just got it to work. No clue what I did right this time. Matter of fact: I got grabbed by the Chaos spawn and slammed around, but for some reason, that didn’t count as getting damaged. Oh well.