I heard of this from some guildies. Apparently you permanently summon a chained doomguard by using this. I have no idea because I'm a warrior, so please try this and let me know.
1) Warlock chains doomguard near caverns of time
2) Warlock duels priest
3) Priest Mind controls doomguard, then BREAKS duel
In theory this stops the timer on the doomguard. I don't know if this works or not and I am new here, so . . be gentle, I bruise easily.