King Duskborne broken

[Rhyono]

Local co-op, Hard mode, he repeatedly would stop fighting and become invincible. Tried 4 times, but it always happened. Eventually skipped the fight by not engaging and going around.

[Egon Spengler]

Yeah, I have had this issue in co-op as well. It seems to trigger the most if somebody dies and leaves the arena or if you move too far away from him. Although I have had it happen without those triggers, just more rare. Usually takes many attempts to beat this guy...