Here how it works
1: Need the Syring to enter the Cave
2: Need a group. Big enought to take down Sher Kar
3: Whole group enters cave with Syringe
4: Person with the Syringe must die and clone and take the 45min lockout
5: Group kills Sher Kar
6: Syringe person immediatly logs off as well as the rest of the group after looting Sher Kar's Corpse
7: Wait 5 mins after logging and log back in. Enter Cave.
If done right the person with the Syringe will get back into the cave and Sher Kar will spawn with it minions for the group.