Play Galaxy of Heroes. Collect as many Nightsisters as you can. Player with the most Nightsisters as characters wins (ties will be resolved by highest star counts on collected Nightsisters). Yes, it's a great excuse to get out and play GoH. Gotta catch 'em all!

There are five Nightsisters -- Old Daka, Ventress, Talia, and the two unnamed Nightsisters. Ties will be resolved by star count, and then highest levels. Some of them are found by shards from regular levels, others through PvP rewards, Bronzium Cards, etc. Keep your eyes peeled for Nightsisters, Tarentum!