Complex sentence: Nick is able to spill Sato off his bike and the two fight briefly, until Nick gains the advantage and decides whether or not to kill Sato for Charlie and for all the humiliation he has suffered.
Split into simpler sentences: Nick is able to spill Sato off his bike and the two fight briefly, until Nick gains the advantage. The scene ends with Nick having to decide whether or not to kill Sato for Charlie and for all the humiliation he has suffered.