Yawp !

I was thinking that it could be really cool to have a dungeon/raid/trial aware of his condition.

RP
A long time ago, a person from our world was sealed in Eorzéa, deep in a dungeon, condemned to an eternity of fight against all those who would be brave enough to come. As time was going by, this person became bitter, slowly changing into an entity that was nothing like a human, ending only filled with the desire to burn its prison to the ground.
Aware of the fact that it was in a virtual world, the entity was not really part of the game, it was an intruder. And that's how it was able to gain the ability to divert the game rules according to its will. If we let it do, it'll soon free itself from its prison, erasing Eorzéa in the process.

Gameplay
The point of this boss would be the mechanics. Because of its situation, it could use all of the game tools.
First of all, the entity wouldn't kill players whose HP reach 0, it would send them back to our world, by disconnecting them with a message such as :
"You really think it was only a game ?"
The player should then reconnect to continue the fight.
Its most wicked mechanic would be to swith two players. Both of the targets would temporarily control the other's character.
During the fight, the entity could have mechanics as :
- Switching effect of damage and heal
- Hiding some part of the interface (HP/MP, hotbar...)
- Switching moving keys
- Confuse the view (blurry screen...)

It would need an appropriate balancing because of all these atypical mechanics but I really think that would be a very interesting boss of dungeon/raid/trial !

So what do you think guys ?