Had him spawn back to back in the same cycle from two different "draconic spirit ember"s. I had killed the first shortly before the second spawned, so not sure if multiple can be up at the same time, but there are at least multiple points they can spawn at, whether or not all of them can be PHs.
He cons db to my 67 alt everytime I have killed him. I've killed him probably 8 to 10 times. The max level may be 68, but he is less than 67 most times in my experience.
ph for this mob can be any of the willow-wisp models (draconic spirit ember) north of the river, spawn time for them is 16 minutes or something like that. spirit stags assist them.