It has a unique death aspect which allowed Klaus to activate the Domain of Death. However, to do that, he had to sacrifice someone...
Naturally, he knew there was no way the seven Heaven Executioners would come at him at once, so he created a trap that he knew they would fall for.
The scroll was a bloodline curse, one that affected all those having even a sliver of the bloodlines of the seven of them.
Klaus knew they would want to kill him before he activated it. So he waited, and just when the brute saw victory before him, Klaus burned 100,000 years of his life force and channeled all his energy into the Law of Gravity.
With that, even a mortal could have caught the axe.
So he went for the kill, and before any of the six remaining could stop him, he activated the trump card he would be depending on if he wanted to have a narrow chance of winning.
Everyone caught within the domain can only rely on the current health because the moment it runs out, death is the next option.
