Mark didn't know that they weren't aware of this truth. When he saw the quest details, he automatically expected everyone to know this.
Now that the truth is out and he cannot do anything about it, Mark decides to act as if it isn't a big deal. "I have my sources." He said to the mage in a nonchalant tone.
After a brief pause, he continued, "Anyway, I don't have much time to waste it. If there's no problem with my request, let's proceed with the deal. What do you say, Mr. Vexiron of the Void realm?"
The mage thought for a bit and replied, "While convincing Lord Xalazar is very difficult, I'll try my best since it is you who is requesting it. I'm sure he will agree to it too. I just need a bit of time. Until then, all of you can rest at the palace."
"Before that, just remove this fuc*ing gravitational effect on our bodies," roared the Demon Emperor, using every bit of strength he got. His face collapsed onto the ground once again.
