I'm really enjoying this event so far. One question how does it decide who you face? I faced Zinda Kent (sniper always on a ledge or cliff) 3 times today, on three different planets (alderaan, nar shadaa, and coruscant) with three different characters (JK, IA, SW). As much fun as it is killing her, I want to kill someone new.

It's a random choice, but there are only a few choices per planet. Dulfy explains it here. But, for example, Zinda Kent is on Dromund Kaas/Coruscant, Nar Shaddaa, Tatooine, Alderaan.