He was granted entrance in the end.
Obviously, Damien was curious about what a man like him had been sent here for. The Dark God wasn't stupid. He knew that Damien could slaughter this envoy if he so chose, but the message he wanted to relay must have been something that needed to be handled with an official process like this, so it was worth listening to.
The envoy sat in an isolated meeting room in the palace reserved exclusively for untrustworthy guests. Damien sat on the chair across from him as he laid some documents on the table.
"I am presenting this to you in this manner so it is familiar to you."
The envoy spoke clearly. He made sure Damien knew that his attire and methods were only the way they were because the Dark God wanted him to know that he could read his past.
Damien wasn't fazed. Sure, it was difficult to get a read on where he had come from since Grand Heavens Boundary no longer existed in this cosmos, but it wasn't impossible.