Duanmu Huai had no idea what the Demon King was up to, and even if he knew, he probably wouldn't care. After leaving the Beast King's territory, Duanmu Huai divided his team into three groups. Their numbers were growing, now nearly a thousand people, and Duanmu Huai thought it was clearly not safe for so many to move together.
So he made the decision to disperse the team, letting Mary and Hei Chuan Chi Yin lead them separately.
The task he gave Mary was simple: carry on the guerilla warfare back into the Beast King's territory. Duanmu Huai was sure that when that raging idiot realized they were causing trouble outside the territory, it would fly into a rage and lead its army to chase them.
At that time, Mary could cause chaos in the rear with the others.
It's imaginable that this could put the Beast King in a state of extreme hypertension, and if it choked to death because of this, all the better.
Though the chances are slim.
