Nina Williams is Jin’s second in command. Jin is faster and stronger than her. He wouldn’t lose to her any day of the week. Jin is too strong of a fighter and is why he keeps winning. Jin’s part of the arc is over on a high note. Jin wins.
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Nina would win any day. She is a highly skilled silent assassin, which requires a great deal of speed and strategy. I am doubtful he is faster, but even if he is she will find a way to get the jump on him.
Well, against normal Jin, then she’d maybe have a chance, but you forget that Jin has his devil form. With it, I don’t think she could keep up with his intense speed or strength.