His Cinta for justice is to the point where he has become sadistic, essentially willing to sacrifice thousands of Navy soldiers in order to kill one man, after already killing the man's brother right in front of his eyes. That's pretty sadistic.
This picture is of him attacking one of his own men, who stood in his way, who tried to get him to stop fighting.
Amaimon from Blue Exorcist. He normally isn't having "fun" unless he's "playing" with someone. Meaning beating the shit out of them and hoping they're strong enough to beat him up after their torment. So he's a sadist and a masochist. But what do anda expect from a demon?