It's, uh. [How to describe this?] Well, erens -- I mean, people who use eres -- their fingernails glow and then...for most people, they just focus the energy around them and make things happen, like -- making fireballs appear from the sky, or ice rising up from the ground. That's crystal eres. And some people they, well, can make themselves stronger and such. We call those kinds of eres iron eres. ...Something like that.