Most uncool, Wonder Woman.

"It's like doing it with your ex. You're not supposed to, and you'll regret it later, but my god it feels soo sweet."

Killing. Just because all of the cool kids are doing it is no excuse to try it out yourself. The sanctity of life is a complicated issue, and can we really judge and condemn our peers? Yes, easily, but human morality... and more importantly the Comics Code Authority says that we shouldn't.

It used to be okay during the Golden Age. But then some asshole wrote a book about it corrupting the youth of America, and that's why the Silver Age was such a sissy.

For villains, it can be... well, it's really fun, and a great way to solve problems. But for heroes, it's a big, big no-no.

And don't think they won't stop talking to you. Because they will. You'll get kicked out of the clubhouse, and lose your healthcare benefits, and you won't be called up when everybody else is going to wear matching outfits. Plus, you'll make Batman cry. And you don't want to make Batman cry, do you?

Compare this Killing with Killing is fun.