People who work in emergency services have this idea of "black clouds" and "white clouds". A black cloud is a person where, if they are on shift, lots of bad stuff will happen. A white cloud is someone who, if they are on shift, nothing bad will happen. I am a white cloud; I've been a part-time EMT for years, and have never been on a high-acuity call. I have partners who have gotten to help set up a medflight landing zone on their second shift, got to work a code on their first week. That never happens when they partner with me.

So, let's say that someone had this at a superhero level. If they are in a place, guarding it, nothing bad will happen there. If it is in the middle of a war, all bombs will miss it, nobody will attack it.

If they are a member of your super team, how do you use them? If you are their enemy, how do you defeat them? What is the most useful way to utilize this superpower?