I don't know if this is canon or not in this continuity, but one of the things that turned Chuck Brown into Kite Man in the comics, was when his son was murdered by the Riddler. Brown's son loved kites, and the first time he flew one, he actually said "Hell yeah!" But when Brown got hooked into Riddler's operations and wanted out, Riddler paid Brown back by poisoning his son's kite string. The boy was rushed to the hospital, but it was too late. Brown's son however, did live long enough to say goodbye to his father. But he also was fearful that he would go to hell for saying a dirty word on the first day he flew a kite.
To honor his son's memory, Brown became Kite Man, and adopted "Hell yeah!" as his catchphrase. So far in the comics, Brown has never succeeded in killing Riddler for obvious reasons. But I wonder, if this origin remains in tact in the Harley Quinnverse, should Kite Man get his revenge on the man who took his son away? I say yes.