Complete Monster/Baki the Grappler


 * Baki the Grapplers Yujiro Hanma, definitely. He beat the everloving crap out of his own son, titular Baki Hanma, so that Baki's entire body, except his face, is covered in scars, killed Baki's mother, and then beat up Baki's friends and allies just to show he could, ALL IN LESS THAN AN HOUR'. Yujiro has enough Charles Atlas Superpower to be effectively untouchable by police and authorities (even the military) and uses his abilities to do whatever suits his fancy without repercussions to put relentless psychological pressure on his son (including, but not limited to, threatening to kill his girlfriend if Baki fails his expectations, and to subject Baki's possible children to the same abuse he had piled on Baki), just to create an opponent worthy of himself. And that's not counting the thousands of people he murdered since he was at least sixteen, or the fact that every fight we've seen him in ended in him delivering a No-Holds-Barred Beatdown while grinning like a maniac, just because it's the sadistic bastard's idea of fun. Or how he treats his other son (i.e. less than dirt on his slippers). Baki puts himself through Training From Hell and a series of incredibly brutal martial arts tournaments just to become able to protect himself and his loved ones from Yujiro. The worst part is that Yujiro hasn't got his comeuppance yet - after about 600+ chapters - although this is somewhat understandable, as his defeat probably would end the series.