"It would prove a liability if you did not, as I am sure you understand as well." A servitor afflicted with the Blood Lord was dangerous, at least when wielding a plasma cannon. "This speed is the result of my bloody sacrifice to my patron, the Lord of Sorcery, Tzeentch. Every khornate would be red of envy if they only dared be jealous of the splendid powers the Lord of Magic grants."
"That is an acceptable alteration. It will not change much. You go where you intend to. I want to crack this one's head open and peek what is inside before I return to the group." he said, refering to the renegade he had dragged with him back to the building.
After the heretek left the building, Setesh begun penetrating the human's mind. Two initial attempts gleaned little, while his third one reached to the furthest mental layer which he promptly made crumble. He consumed all there was to know, to offer whatever knowledge there was to his Dark God, especially that which Setesh had no immediate need for himself.
Instead of bringing his newly found sacrificial victim with him, he swiftly split the human's skull in two with Vra'tzaen, to leave keep that which was in the human's head for Setesh and the Lord of Lies only. He had already realized it was pointless bringing a renegade with him into battle. He had no way of just leaving the human there, waiting for the sorcerer to return like a well-trained slave. After slaying the human, Setesh sped back to the rest.