The new girls introduced this event [v3.2] are: Mia - Starchaser (<-- click to go to her article) Click here for my take on how Starchaser affects the game and its meta.
Haru - Raikou (Raikou is currently unavailable)
Raikou is freely claimable between the 27th of November and the 18th of December by competing her puzzle collection game
From the 27th of November you can also get one 5* operative and their 5* weapon for free in the "Heartbound Induction/Arsenal Accord" in the Quartermaster.
This lets you pick between Lyfe IS, Siris Ksana, Cherno Enigma, and Katya Blue Bolt, and their asociated 5* weapons.