After surviving such a deadly attack, I was hovering in the middle of the massively messy art Iris had just created. I was planning to retaliate, but I would be futile as I did not have a weak spot on her. Instead, I attempted to resolve the situation through dialogue.
"From your reaction, it seems like I hit the mark. Not only once, but you did twice. You really don't fail to entertain me, Raphael."
"...What are you talking about? What makes you think that I have that ability? What is your basis?"
Not only did she catch me using the Impregnable Fortress, but she also knew how many times I cast it. I had thoroughly concealed my skill by using the Unique Skill: Mystic Artist to apply Perfect Concealment to each cast, removing any trace of mana, energy, etc. But my efforts seemed fruitless in front of Iris.
"You ask me how I knew? It's as simple as... I used to know someone who has this ability."
"What..?"