Yes, the "pure rage" comment indicates the severity of the beating you gave this guy.Before you go into any sort of court situation, rethink your language about this incident.
"I beat the crap out of him" may sound nifty, but seriously, how many licks were thrown? After you kneed him, did he go down, were you hitting him while he was down? Did he come back at you? Did he hit you any more times? You hit him in the face how many times? Most fights do not really have many licks thrown, and be careful of the semantics of the language you use. If you do get to have an attorney, they will be talking to you about what to say and what not to say.
Stop talking to other people, including school officials, your friends, etc about this.
But what we are interested in is as someone said, is what does the summons say?
All the law allowed you to do would be to fight him to the extent it deterred him from doing you further harm. Did he hit you after the initial punch?