I'm wondering if you're one of them players who would purposely block someone in a PVP area. Never letting them leave the map. I had that problem in the past while being in the Battle zone and had some random mage blocking me in there during the event of obtaining the Snow Slime Mount.
1. Dying in abyss spawns you at the door to leave, so no worries there.
2. This guy is a perm 6x end build cleric, so no worries about him spawning you. At the very least you can tank out his full rotation to open the door