Power, immense or otherwise, always comes with a price.
That universal law is true for everyone, and the Tathamet brides are not an exception to that rule.
Thus far, they have avoided paying the toll on their unfair abilities due to the nature of their relationship with their husband.
Because they share his life force, their own individual talents are enhanced by his energy, as well as bestowing on them a few unique abilities.
However, when they push their abilities beyond the umbrella of protection that Abaddon's marking gives to them, will all begin to experience certain drawbacks.
They won't all be as bad as Bekka's mind you.
Most of her struggle came from her age and the kind of divinities that she possessed.
Bekka is only twenty-two years old.
And her body houses not only gluttony and sloth, but void of all things to boot.