Rex's hands were tied.
At this moment, he had several powerful enemies who wanted nothing more than to see him die.
He already has things in mind that he needed to do, which many would consider immoral—and he had resolved himself to go through with it. But even so, there was no need for him to add another powerful enemy on his back.
Being High Lord Rasha's enemy would be catastrophic for him.
And more importantly, it would only distract him from achieving his goals.
So, he needed to restrain himself from going overboard. This is him holding back. Despite what High Lord Rashal instructed Liebert to do, he decided not to pursue it right now. He was in a pickle and couldn't have his focus split again.
I'm showing you respect, Rashal. I know you're sharp enough to notice this.
Informing what he wanted to say to High Lord Rashal's face through Liebert should be civil enough.
He was quite sure High Lord Rashal would understand it and accept this outcome.
