In the MMORPG genre, boss battles had always been an important part of the gaming experience. Quite a few players played specifically for boss fights. One could even say that everything else was just decoration—the most fundamental gameplay loop was defeating a boss, obtaining equipment upgrades, and then defeating an even stronger boss.
To that end, game designers had pulled out all the stops, creating all kinds of baffling mechanics for boss battles: moving and stationary swords, poison transfers, mahjong-style targeting, swords from all directions... Later on, mechanics as outrageous as observing the future and stopping time would even appear. Players had to deal damage while watching the mechanics, ensuring they had a sufficiently brain-overloading gaming experience.
Don't ask whether the experience was good. At least it guaranteed that you would be busy.
Sharing a death sentence was one of the more common mechanics. Its countermeasure was right there in the name: everyone had to share the death sentence. However, Corpse King Long You's attack was not a simple shared death sentence. It was also connected to a raid-wiping enrage. If they could not withstand the shared death sentence or dodged it, the boss would immediately enter its enraged phase.
Generally speaking, ordinary dungeons would not have mechanics like this. The "Messengers" divided dungeons into five dimensions: regular, difficult, extreme, desperate, and special. Thieves' Den belonged to the final category, the special dungeons. Only dungeons of difficult rank or above could possibly have raid-wiping mechanics, but those dungeons all came with obvious warnings. Forest of Bones was merely a regular dungeon.
Thinking of Skull Tower and the Red-robed Demonic Beast, which had also possessed powerful mechanics, a guess arose in Yan Qing's mind: Did activating the karma bar raise the strength of elites and Demon Kings by an entire tier?