Reed basically saw red the moment the purple skull started laughing at him, not because he was taunted by it, neither did Sarah use her darkness nether to mess with his mind, it was because he felt humiliated, here he was using his Domain to suppress the crazy girl and she still had the leisure to do something as trivial as making a mere battle aura creation laugh at him.
It meant that even as of current, she didn't feel pressured in the slightest, on the other hand, simple mana pressure wasn't the only way to use a Domain to mess with the enemy.
"Let's see you tough this one up you, brutish bitch!", shouted the Asmadian Lord as he beckoned with his hand, causing dark pink flames to lit up on the air in front of Sarah, before they went off in the form of a large explosion.