A battle between you & Itachi takes place. You attack him, but Itachi Uchiha—intelligence gleaming in his eyes—dodged every attack, with effortless grace.
You manage to catch him off guard, thinking he’s done for.
Itachi: “Am I? Before you do anything, you should take a good look at yourself.”
His words send chills down your spine… as you are quickly trapped/killed etc by your own attack. Itachi had already decrypted your tech/hax/attack etc & used a "genjutsu reflection" sealing your fate.
Itachi: “You are already under my genjutsu” kunai at your throat
[Narrator: Right from the beginning… when you saw Itachi’s Sharingan, you were already under his genjutsu then. His skill & prowess with genjutsu is stupidly broken. He finessed you thinking you’ve won. You can’t beat this Genjutsu God. He even has a type of genjutsu to trigger in case of his death.]
[Intelligence: Extraordinary Genius Itachi was an outstanding genius with prodigious talent.]
Itachi is a marvelous tactician. His ability to formulate & carry out short & long term strategies to absolute perfection is nearly unmatched in the verse. His ability to anticipate the actions of others & the outcomes of certain events is so accurate that it borders on actual foresight.
He truly thought of every single possibility, & had contingencies for all of them, even after his death
Itachi's genius level intellect & brilliant strategic mind carry over to combat as well. His style revolves around calmly analyzing his opponent(s) & the situation he's in. Based on his careful & thorough, albeit extremely swift, analysis, he's able to derive a plethora of useful information including, his opponent's motivations, goals, moves, abilities, weaknesses, methods of countering their abilities in the most efficient way possible etc.
He is also extremely creative & adaptable
Itachi: “You’ve checkmated yourself”
[His Infinite-IQ-Genjutsu™-brain ever elaborate. Genjutsu within multiple genjutsu. Checkmate GG]