In truth, Lucifer could also feel this change, but he didn't act for 2 reasons, first was that there was no point him butting into other people's business but the second and more important one was that he knew Lucius would either be at the forefront of this war, or he would singlehandedly put an end to it. Elysia on the other hand was not as nonchalant as Lucifer, perhaps she could even be called nosy as she had kept tracks of every clan or race within her scope and so she planned to send her angels down to either mediate, or to help any particular race/clan she agreed with.