I can't seem to get Split Personality, even with the advice of DPSing one at a time. I've gotten close using an AE approach, but I don't understand how people 5-box this without a tremendous amount of luck, or a specific class mix. When I use the single target dps approach, I am able to Hex all 3, but it wears off before I can manage to DPS each low enough. When they are all casting, it is all I can do to heal my group. I can't DPS at the same time.

All I have left is Split Personality and Make it Count. I think I can get Make it Count, but only 1 try a day makes it hard.

If I can get more detailed help on Split Personality, I would really appreciate it.