Derik dropped Cyrus at the core of the god vein and allowed his friend to use the energy to help stabilize his realm and increasing his chance of making a successful breakthrough into the true god realm. Even after dropping him off Derik had no intentions of sticking around and watching Cyrus cultivate. He already hated the fact that everything is moving at a pace far slower than what he wants but there is nothing he can do about it.
While many may believe his worry lies with the beyond, cosmic beings and Blake but in reality, he wasn't bothered about them since he knew their deaths are assured. In fact, if he should go against the Beyond and the others now, the only person he would be worried about in that group should be Blake but with Cyrus by his side he's confident there is no foe they can beat. Right now his real worry is Lucien of the new god vein. The inheritor of the power source he wants.