Event spawn on GL. There are 5 Vanguard Controllers, each on a Nightmare, and they seem to be the main thing to take out here. Everything else seems to be summoned by these 5, and after a time period of about 2 minutes they all dispel, in a puff of black smoke, just like when they die. Not all at the same time, in groups. I think because different Controllers summoned them at different times. I've also seen puffs of black smoke where I saw nothing, so there may be stealthing spawn summoned as well. Some of the spawn, the lowly sorts, can be pulled away from the area. But others, like Wisps, teleport back. The spawn on GL is in the northern parts of the city buildings. The bank area is safe...for now.