I am so sick of arriving to a S rank enemy for it to die just before I arrive. Happens frequently with my FC friends as well. I cannot get there any quicker, I move immediately upon receiving the call. Many people are courteous and wait enough time for the vast majority to arrive but there is always that one impatience person who starts the attack and then everyone else joins in because they dont want to miss the kill.

So hence the npcs need to have more hp to allow people to arrive. The HPs needs to adjust based on the number of players present. The enemy should take 5 minutes I think to kill and that will give people enough time to get there. If you are only 1-2-5 people, its 4am, no one else wants to come then it shouldnt take 10 years to kill so hence the sliding HP amount is required.