Nani wished on Holika day that Taps be free from "buri nazar" and Taps has a "Prahlad" like child......so the wish came true - Satya will leave Taps alone as Rathore will kill Satya if anything happened to Taps or his child.....off course if Taps child has Rathore's gene he will have some fairness/sensible genes....