Allergic to Evil/Playing With

Basic Trope: Being near evil makes a character physically ill or weakened.
 * Straight: A character feels sick or weak every time he gets near the villain or one of his minions.
 * Exaggerated: A character will die if he gets within a mile of anyone not completely pure of heart.
 * Justified: The artifact giving the villain's side their power releases some sort of chemical into the air that the character in question is allergic to.
 * Inverted:
 * Being near good makes a villain physically ill or weakened.
 * Being near evil is the only thing that temporarily relieves the symptoms of a good character's chronic illness.
 * Subverted: A character gets sick the first time we meet the villain, and says something about the villain's 'bad vibes', but it turns out that he really did just happen to catch a cold, and it was a coincidence.
 * Double Subverted: A character gets sick upon getting close to the villain, but stays sick even when they're far away... and then it turns out that the hero's group has a spy whose evil was causing him to continue being weak.
 * Parodied:
 * Every time a character tries to pull some kind of prank on an unsuspecting person, the character this trope applies to will involuntarily start coughing sneezing, or vomiting on the spot, alerting anyone nearby.
 * The character sneezes any time anyone even says the word "evil".
 * Deconstructed:
 * A character is constantly sickly, and his health is painfully declining from his various encounters with villains, or maybe just the people around him.
 * Alternatively: A character's health fluctuates every time he struggles with temptation, taking a turn for the worse if and when he gives in, as he's allergic to his own evil just as much as he is to everyone else's.
 * Reconstructed: A character gets special pills from his doctor to keep his evil-related weakness in control. It's still just enough that he can sense when something bad's around, but it doesn't really cause any pain.
 * Zig Zagged: A character has a variable allergy to evil (from sneezing to coma), and the canon concept of "evil" varies all the time, from "petty" to Complete Monster, making the whole trope completely unreliable.
 * Averted: Evil is around, and nobody gets sick because of it.
 * Enforced: "We need some kind of canon explanation for why this character was with the hero all the time, but didn't really fight in any of the big battles, especially since he's a Badass in the smaller fights. Maybe he gets weak when he's around really evil guys?"
 * Lampshaded: "Uh-oh, I'm sick. Guess that means someone evil's around."
 * Invoked: The evil villain intentionally tells his minions to ignore all personal hygiene, in the hopes of making the heroes become weak in their presence. Who cares if a few Mooks end up getting sick, right? It'll be worth it in the end.
 * Defied: A hero won't approach evil without making sure his vaccinations are up to date, he's taken all his vitamins, etc.- he doesn't want to get sick in the midst of battle.
 * Discussed: "Wow, you had to start sneezing now, right before we have to confront Lord Evil." "Hey! Maybe it's some sort of cool evil-detecting illness! Then you'd love me for it!" "Nice try, Bob. No more fantasy novels for you."
 * Conversed: "I really wish Sidekick Joe would get some awesome fight scenes, but he's always 'sick' whenever the villain shows up. That's really disappointing"

"Ha-CHOO! Back to *sniff* Allergic to Evil."