Newt Scamander was in sent to a reorientation centre following his expulsion from Hogwarts, viewed as an unstable and improper omega. By the time Theseus managed to gain custody, Newt was broken and terrified. Theseus cared for him as best as he could, and years later Newt still has the occassional nightmare but has handled the trauma well enough - until the events of New York.

Kinkmeme: http://fantasticbeasts-kinkmeme.dreamwidth.org/1184.html?thread=1441952#cmt1441952
AO3: http://archiveofourown.org/works/9239051/chapters/20952902