So this is a story related achievement however....
You have a boss fight against...
And you will find that you seem to do pretty much no damage against him, even though the fight is easy and you don’t die, after about five minutes I found I did practically no damage against him, so looked up a video
To damage him you need to do a long combo. I found Tungar with
(or whichever button he is for you) does a good combo. After you spam all three of Tungars attacks it starts damaging him and that’s when you go in on him with all characters.
I would recommend having Razmi on your team to heal. He has one attack that builds up your iddhi bar, so heal when you can to make this long fight easier on yourself
Once you beat him and watch all the cutscenes, the achievement will unlock