Chapter one:

Getting kidnapped, turned into an assassin, caught by another organization, unlocking powers.
What else could possibly go wrong for Katerina/Casey ,
Oh yeah, getting involved with New York SVU.

AN: she isn't born a Tribrid, she becomes one through red room experiments when she was very young

Black widow x reader
Some Iron dad x reader moments

I don't own any marvel, vampire diaries or law and order svu characters, etc
Other than my own OC's