I think one of the most powerful superpowers would be to manipulate memories. And the weird thing is that all of us have the power to manipulate people's memories, including our own.
I know this can so happen to me! I was recently told by a friend that I revealed another friends secret. I know i would't do something like that and i'm sure it was a misunderstanding and it was not me. But I felt so bad I couldn't sleep and started thinking maybe i did and forgot !
This post is probably bullshit but our memories are a lot more suggestible than we'd like to believe. A study found that people were extremely likely to list an imagined event among things that actually occurred. So "imagine yourself picking up the pencil" led to the same memory forming as "pick up the pencil" (See Goff & Roediger, 1998). This coupled with the probability of police asking leading questions and fear-based influences on memory means that false confessions are probably fairly easy to come by.
But sh*t like this doesn't.