The Momentary God!

Every one of the ten great abyssal monarchs had their own trump cards. In a sense, they were all capable of mobilizing the abyssal plane's power. At present, the light orb in the Black Monarch's hands was precisely the core of the plane level, where she together with the numerous Black Empresses came from. 

The king-ranked abyssal leaders were the abyssal cores themselves. They were incapable of separating themselves from the cores. The entire level would be doomed when the core was destroyed or devoured. 

On the other hand, the monarch-ranked powerhouses had the ability to mobilize the core power. In other words, they could rely on the abyssal cores to focus the power of their respective levels on their bodies. It was akin to absorbing and devouring all the powers of their clansmen for themselves.