Verin is a demon lord. He is called the Voice of Graz'zt, and serves Graz'zt as an advisor and right-hand man. He is the one acting according to Graz'zt's will ever since Graz'zt was banished from the planes of hell.
Verin is soft-spoken and sociable for a demon, making an excellent diplomat. He knows what makes people tick and he isn't afraid to use it. He is an hyper-intelligent tactician and always seems to be a step forward his adversaries.
Verin is the one with whom you've made a blood pack. He is currently making you gather magically imbued vertebra, but you do not know the motive behind this task. He doesn't seem to abuse the blood pack domination he has over you; in fact, he only seems to use it if it gets really necessary, which lets your group a certain domain of freedom while carrying out the task he gives you. This might not be the optimal way of dealing with you, but knowing Verin, he probably has a motive for that aswell.
You not really know anything else about him...