Kapitel 495: Bring Beelta's Head.

The way they joined the house of Chaos was very abnormal but that's all in the past. The family has behaved like a normal noble family ever since. What is always current is the Lord of the house of Chaos. Their lord is abnormal and has remained abnormal. 

The Lord of Chaos could cross ranks to kill demons of higher ranks. He terrorized the domain of high-rank demons as a mid-rank demon. High-rank demons had to band together to face him and yet, they failed. Then he evolved and became a thorn in the side of his demon lord as a high-rank demon. 

The Lord of Chaos is a legend in the 541st plane of the abyss known for his legendary feats and unreal prowess but what topped it all off is that he rose up from being a fledgling to becoming demon king in less than 300 years. That kind of progress is a hundred times too fast. It is very abnormal, to say the least.