A tough, feared gangster embarks on a rampage of killing to avenge his murdered son. But when his obsession for justice steals his presence from the rest of his family, he’s forced to choose between avenging his son, or saving the family he loves.

When a gangster's son is murdered his obsession for extrajudicial justice forces him to choose between revenge for the past or saving his family's future."

25 words. 'Kin A !

reworked to be 25 words:

"When a tough gangster's son is murdered his obsession for finding the killer forces him to choose between avenging the child he's lost or saving the daughter he loves."

The mix between action and drama is almost always a good combo in my opinion and I think this idea is a good one. The plot sounds like it could have something for everyone. He is torn between two choices. My advice, make it a little more complicated than black and white. Spice things up. Its a decent idea though. Good luck.