So, why didn't Yang die from Atam's attack? As shown in the pictures below, Atam's attack should have lliterally cut Yang in half
but instead, only her arm was sliced off instead.
If you look at Atam's attack closely, you can see that right before Yang was hit, there was a red-colored semblance in a shape of a Raven. This, however, might not be what many think it is, which could possibly be a portal made by Raven, her mother in an attempt to save Yang from Atam's attack, but instead for this time, she was not able to protect her daughter from getting her arm sliced. This, however, is only a theory. Another possible reason that Yang didn't die was because the creator just didn't think it was time for a important character to die. I give credits to the rightful owner of this theory. This theory is not necessarily correct.
CREDITS: