Hello,
This is due to how barriers interact. Attempting to put up the same barrier twice in a row causes the barrier to fail. I will contact the devs and ask if this is intended or not and return with more information once I know it. Thanks!

it makes sense barrier gets vanished when you use mystery next time yet mystery damage also fails seems bug . Thanks for the respond anyways :)

ye the same thing happen with itachi kimono paired with red lotus... if he kills and got reset, next round when using the mystery the barrier is gone + no damage

i think the system programs to have the barrier active as the damage is dealt... if no barrier (or disable the barrier), no damage.

YujinTakara is correct. The mystery cannot "half activate." it either activates in its entirety or it does not activate at all. Since the barrier is already present, when you cast the mystery a second time, you are cancelling the barrier and cancelling the mystery. As mentioned, I am looking further into this issue to see if this is intended or not. I will let you know once I hear word back.

cool looking forward to hear back from ya , thx again. .

And @Yujin . big fan of your ninja exam videos. that helped me a lot as a most-of-the-time fm. Keep good work