One who is so awesome that if they were king or queen he or she would kick everyone's ass. And when people ask how ruling the world is, he or she would be like, "see that ass over there. Kick it. Didn't that feel good? Now imagine kicking everones ass everyday. That's what's it's like ruling the world. Now turn around so I can kick your ass." And that is kickasstastic.
Holy crap!!! I just saved that baby from getting hit by a runaway grocery cart, and the baby's mom gave me twenty dollars. That's kickasstastic! or I'm kickasstastic!