Bad Guys Do the Dirty Work/Playing With

Basic Trope: A villain commits a villainous act that furthers the heroes' goals, allowing the heroes to benefit without getting their own hands dirty.
 * Straight: The Super Troper team has subdued Master Destruction, but they know that it's only a matter of time before he escapes his Cardboard Prison and wreaks havoc again. Luckily, Emperor Evulz shows up and kills Master Destruction for them.
 * Exaggerated: Emperor Evulz appears and takes care of any uncomfortable act a Super Troper is faced with, from executing super villains to tactfully pointing out that, no, that new cologne really isn't very flattering.
 * Justified:
 * Emperor Evulz considers himself more of an Anti Hero and believes it's his job to do what others won't.
 * Emperor Evulz maybe irredeemably evil but there are some line he won't cross. Master Destruction, however not only crosses them but pole vaults over them. He then calls out the heroes on this "so you can sleep easy without guilty conciseness."
 * Lawful Evil Emporer Evulz wants to stop all of the rebels in his nation. Both the Chaotic Good Super Troper and the Chaotic Evil Master Destruction.
 * Inverted: Emperor Evulz likes to think he has standards, and as such won't execute and unarmed prisoner. The Super Tropers, on the other hand, are willing to do anything for the greater good.
 * Subverted: Evulz offers to "take care of" Destruction, and drags him into an alley, loading his weapon. As soon as they're out of sight, he unties Master Destruction.
 * Double Subverted: ...then he shoots him as he's "trying to escape."
 * Parodied: The heroes keep Emperor Evulz's phone number and call him whenever they need someone to Shoot the Dog.
 * Deconstructed: The fact that the heroes needed to rely on a villain to bail them out of a problem puts their convictions and abilities into question. The question on whether or not they'll need to become Necessarily Evil also comes in.
 * Reconstructed: After receiving a Hannibal Lecture from said villain savior about being morally cowardly and ineffective, the heroes realize that now and then they will have to Shoot the Dog--but only if all other options fail first.
 * Zig Zagged: Evulz draws his sword and advances on the helpless Destruction. Suddenly, Hero Harry interposes himself between the villains and says this is something he's got to do for himself. He puts a gun to Destruction's head... but he can't bring himself to pull the trigger. Evulz taunts Harry for his lack of moral fortitude and grabs Destruction himself. Then he flies into the air and escapes with the criminal. The heroes track him down, only to discover that Evulz is now subjecting Destruction to a Fate Worse Than Death, as mundane execution is too good for him. Then said fate turns out to really be Training From Hell to make Destruction even more powerful and evil...
 * Averted: The heroes either Shoot the Dog themselves or let a dangerous villain escape justice.
 * Enforced: Cold-blooded execution would make the heroes seem less sympathetic, so it falls to Evulz to permanently tie up Master Destruction's story.
 * Lampshaded: "Oh, come now. Don't act so self-righteous. If I hadn't come along, you'd have had to do it yourself!"
 * Invoked: The heroes take care to drive Master Destruction onto Evulz's stomping grounds before subduing him, and go out of their way to delay his extraction to maximize the chances of Evulz stumbling across them.
 * Defied: As soon as Evulz shows up, Paladin Paul threatens to charge him with murder if he harms the prisoner.
 * Discussed: "Looks like only the bad guy can solve this problem. Super Troper doesn't have the stomach for that sort of thing.
 * Conversed: "Super Troper! If you aren't going to kill Destruction, then I, Dr. Evulz will!"

And just when you think the Big Bad has won, your old nemesis appears and takes you back to Bad Guys Do the Dirty Work!