Better question is why is his clan leadership doesn't do anything about it despite repeated ss.
I believe the spawn time is around an hour, I used to kill the archer ph(was trying to collect the bows) and come back in around an hour and usually the dude had respawned (99% of the time it was another PH).
starts at 1 hr 20 min for 185 and then add 10 minutes for each tier boss after.
Topic: What if all bosses were as punctual as the 200 event dragon?