It was a frown, and instead of evading the Invincible Scimitar that Shane had already swung towards her, Megane's eyes were just turning pitch-black as she released something she had been instructed to hide from everyone.
It was an [Forbidden] ability she had obtained from the Sin of Gluttony which she could only activate if she used up her entire mana while being in a life-threatening situation that was unavoidable.
Megane had several dozen skills to make use of, but none of them would have been enough to protect her from the Invincible Scimitar's attack.
Shane had simply been too fast for her to realize it.
This was the problem a marionette had! Her reaction time might be superior to everything, but she had restricted her strength according to the instructions she had received, thus forcing her to activate the forbidden ability. Using a hidden ability was always faster than unveiling restrictions, thus saving precious time in a battle.