Barbatos was awakened, not because he noticed that his power had diminished, but because he suddenly found that he had gained quite a bit of power.
He was the Source of Darkness in the universe. All darkness in the universe was actually part of him, like a person's limbs or patches of skin.
Whether Bruce had previously siphoned off power through various projects or Schiller had used it to fill Constantine and harvest something from him, each amount had been tiny, rather like scraping therapy. Barbatos had been busy and had no time to care.
All that power had been taken away bit by bit. The amount in any single instance was far too small. It was like a human losing a flake of dandruff without noticing; Barbatos had felt almost nothing.
But if every flake of dandruff someone had ever shed suddenly grew back onto their body, that would feel quite different—especially if it did not appear on their head, but on their hand. It was practically like growing an extra finger. It would be strange not to notice it.
Schiller and Bruce released all the power they had stolen at once, and Barbatos immediately sensed something was wrong. What was going on? Where had this power come from? Why didn't he remember putting so much power into that place?
With something wrong, Barbatos naturally wanted to investigate. But the problem was that he could not get out. The barrier Michael had set up was still there; he had no way to leave the Source of Darkness at all.
But being unable to leave did not mean he could not investigate. Barbatos immediately called his dear son Bruce and told him to hurry over and check what was happening.
Bruce immediately assured him over the phone that he would