Just like before, Blake patiently waited behind the tree, concealing his existence while observing the five humanoid demons that had been caught by his binding darkness tendril spell.
The reason why he didn't bother with the five humanoid demons right after successfully catching them was exactly because that was what he wanted to test out.
He saw the humanoid demons struggling, trying to save themselves from their current predicament. Then he watched some of them simply stop trying after the darkness tendrils latched onto their bodies tighter and the pain that they felt began to intensify with the sharp tips of the darkness tendrils burying themselves deeper into the humanoid demons' skins.
And after a full 20 minutes had passed, all of them had finally stopped trying to break free and just accepted the fact that they were unable to do anything about their current situation.
And this was where Blake observed them even keener than before.