"I want him fucking dead! Hurry up and break through that barrier! Something happened in the Underworld, and I can't access it anymore!" Karyndra was pissed off to the maximum.
After leaving the demon world to return to the angelic realm, she realized that she had been played. She didn't think Zion would trick her since everyone knew he meant what he said, but for the first time, he didn't.
After raging for a bit, she tried to return to Azmorath's side, but the gods attacked them at that moment, forcing her to deal with them.
Since the gods themselves were involved this time, she had no choice but to release the sentinals to cover her back and handle things while she traveled to to demon world, but once she did, something stopped her.
Just like how a barrier protected the middle world, one also protected the demon world. That's how she knew something had changed.
When she contacted Azmorath, he didn't answer, and that got her worried.
