Newt's core personality is kind, gentle and compassionate, but it's to the point that his heart gets hurt easily.
The Scamanders are a pure-blood family, and due to pressure and his parents' expectations, Newt developed a pure-blood personality to handle social events/bullies at Hogwarts (think cold elite elegance, like Lucius and Narcissa Malfoy, without the snobby attitude).
Up to you whether Newt knows about his other personality.
+ If pure-blood!Newt is super protective of kind/gentle!Newt. ++ If Newt adopts Credence, someone says shit about the Obscurus, and pure-blood!Newt comes out to utterly shred someone to pieces with words alone.
Multiple Personality Disorder!Newt (Gen or Graves/Newt)
The Scamanders are a pure-blood family, and due to pressure and his parents' expectations, Newt developed a pure-blood personality to handle social events/bullies at Hogwarts (think cold elite elegance, like Lucius and Narcissa Malfoy, without the snobby attitude).
Up to you whether Newt knows about his other personality.
+ If pure-blood!Newt is super protective of kind/gentle!Newt.
++ If Newt adopts Credence, someone says shit about the Obscurus, and pure-blood!Newt comes out to utterly shred someone to pieces with words alone.