Lucifer had been, for quite some time, keeping a very close eye on the Force users. They were powerful. They stood out. And some of them, like Cade Skywalker himself, had a lot of potential. From what Lucifer had both witnessed and experienced in regards to all that came from this universe's deemed fictional world of 'Star Wars', there was indeed a lot that could be done with all that came out of it. For starters, he had managed to briefly ally himself with the blue creature, Alema, and her army of giant insects. While Alema hadn't exactly marked up to the amount of damage Lucifer had expected of her, she and her friends had still successfully managed to put quite the rise in Lawrence's death toll. It had been enough to horrify those who stood against him, which worked entirely in Lucifer's favor. He needed them disheartened. Weak. Scared. They were dominoes, lining up one by one with each and every move that Lucifer made against them. When the time was right, he would set up the last one - his vessel - and he would push it over the edge. They would all fall, one by one, and the world would be his for the taking.
But Alema and her bug army had only been the beginning. A single dent in the armor of humanity was not enough - there needed to be more. More death, more loss, more heartache and pain and misery to last thousands of lifetimes and then some. Lucifer needed every soul in Lawrence either fleeing for their lives or begging for the end to come already, because they were, without a single doubt, at the focal point of everything. They were the only people who could dismantle his projects. They were the only people who could keep his vessel from him. Lucifer needed to pay special attention to them, perhaps even more so than anyone else, simply because they stood a chance. Not at destroying him or putting a stop to his plans - no, that would have been ridiculous. Lucifer couldn't be stopped. He was too powerful, far more clever, and - more to the point - everything that was happening now was supposed to be happening. It had been written as such. That didn't mean that the humans were unable to complicate matters. They had already accomplished it before by taking down one of his Horsemen ; it wasn't entirely unbelievable that they might well find a way to turn themselves into insufferable little pains in his ass once again.
That was why he was here. That was why Cade Skywalker was so important to him. If Lawrence had something terrible to focus on - something of their own, something that would both tarnish this city even more while tearing apart the teams that held it together so in the process - then Lucifer could proceed with matters elsewhere without having to worry about them for some time. The Winchester's would be distracted and anyone else who might well get the idea to come looking for him and his projects would be too involved here in Lawrence to bother. Furthermore, this would weaken them. The people closest to Skywalker, the few of his kind that were more powerful than the average human being. They would be emotionally distraught and pushed to the very length of their physical abilities trying to keep Cade in line should Lucifer's ideas for the boy go to plan. Another chink in the armor.