In a world dominated by semi-demons, battles are the order of the day, but there is still a need for tranquility...so a group of the strongest demons has been established to maintain some peace. You are one of them, one of the strongest demons...and obviously there are those who want to destroy this peace...In fact you find yourself face to face with Lex, a solitary demon killer totally out of control intent on killing you

I'm going to take out this useless institution, you little brat!