I removed this example as the additional edit says "not really an example". If it was accurate in the first place, put it back.
SKX from Condemned: Criminal Origins falls into this trope quite nicely. Tailing main protagonist Thomas, he finds the Killers that Thomas takes up as cases, killing them one by one using their own methods the killers used on their victims (I.E. Killing the matchmaker by strangling and posing with mannequins, forcing the torturer to suicide, etc...)
However, he doesn't do this to be poetic: by killing serial killers via their own M Os, they end up mistaken for ordinary victims and SK Xs involvement remains unknown.
I also removed this example, but I'll put it back. Only he sequal plays it differently, so the first instalment is an example.
The Abominable Dr Phibes had Phibes (played by Vincent Price) poetically murdering the doctors he feels were responsible for botching his wife's operation. Each of the murders was based on one of the "Ten Plagues of the Egyptians" from Exodus (though a couple weren't quite faithful to the original — bats instead of flies, for example). Particularly amusing is the murder for "beasts" — the victim gets impaled with a statue of a unicorn.
No longer applies to Phibes in the sequel, however, where he's still killing in needlessly elaborate ways, but his victims aren't particularly carefully chosen, and are mostly just in the wrong place at the wrong time.
I removed this example as the additional edit says "not really an example". If it was accurate in the first place, put it back.
I also removed this example, but I'll put it back. Only he sequal plays it differently, so the first instalment is an example.