Powerful

I recently watched Amy Cuddy's TED talk about How Your Body Language Shapes Who You Are.  She talks about powerful body language both as others perceive you and as you perceive yourself.  I would use this information when using Powerfull to talk about building confidence.  I would also use it to discuss difference between feeling powerful and feeling powerless.
Love her quote "Fake it unless you become it.!"  Watch here Amy Cuddy talk.