He’s back. Apparently being stuffed into pigs and drowned wasn’t enough.
Legion’s a twisty, dangerous, practically unstoppable demon to deal with, because it is everywhere. It possesses groups, driving them together into powerful hive minds, and its always expanding, gaining more and more people. Killing one of the hosts kills off some of the Legion’s power, but so long as it has some hosts it can build up more.
The true danger, however, is in Legion gathering its power back together. It won’t do this unless badly threatened, desperate, or overcome with rage or vengeance, but by drawing more power into a single host it can make itself incredibly powerful, but risks losing a lot more of itself if the host dies.
Perhaps more disturbingly, though, Legion isn’t just a mindless assimilating machine. Most of the people it hollows out, devouring their souls to grow in power, end up with touches of the central personality. Legion is actually well read, charming, entertaining, and a lover of the finer things in life. It almost never uses physical violence unless attacked, preferring instead to burrow into new victims using spiritual energy. It’s awful hard to make a move against any of Legion without it drawing in the proper authorities to defend it.