The Oracle headquarters was considered one of the most secure locations in the world. It was located in a pocket dimension, and unless you had the mark of the Oracles, you wouldn't be able to find the gates, let alone enter.
Many tried over the years, and they all failed miserably.
Basically, the Oracle headquarters was a fortress that couldn't be breached.
However, it was breached today, and the one who did it was the last person they wanted to see.
They didn't know that the hunter they had sent into the Dead Region had infiltrated their domain. They never saw that far into their reckless planning and now, it came back to bite them in the ass.
But of course, they didn't recognize her, and while it would have been polite to talk things out, they knew she hadn't come for conversation.
After all, she breached their safe space and was exuding potent killing intent. There was no need to think otherwise.