The whole series up to this point Tory's almost been a supervillain. Easily one of the most violent and angry of the Cobra Kais and then this season comes along and hits the brakes on all that.
Because she's not a supervillain, or some kind of psychotic monster. She's an angry, troubled kid in an incredibly difficult situation with nowhere to turn to.
I just thought it was great that as soon as Tory starts getting some actual support in her life she starts changing in a big way. To the point she's actually apologizing to Sam for accidentally elbowing her in the tournament when the two of them have had a bloodthirsty rivalry for the series up to that point.
Kreese: Fuck you. /undevelops your character