Crimson Eyes

Crimson Eyes (真紅の瞳 Shinku no hitomi) is the Quirk used by Itachi 
Description
This quirk resides within Itachi's eyes, and has a secondary ability, which is the sealed away Fire trait. The main ability being the eyes, have two forms, the Crimson Eyes and the True Crimson Eyes, both unlocking different sealed abilites. 
Crimson Eyes: The Crimson Eyes have two abilities, the first ability being slowed vision, this allows the user to see their opponents in a slowed manner, and attack accordingly, this is the most passive ability of the Crimson Eyes, allowing for Itachi to use this ability multiple times, without hurting his eyes. The other ability being, the seal released on the Fire trait, allowing Itachi to summon fire to attack with. This fire can be manipulated multiple ways, and leaves Itachi with many attacking options/
True Crimson Eyes: The True Crimson Eyes have two abilities, the first ability being the Sacred Flame, this flame is completely black and appears wherever the user is looking and, will constantly burn until the target is burned up or Itachi releases the Sacred Flame. The final ability that can be unlocked is the Crimson Samurai Suit, this ability takes complete concentration to unlock and use. 
Crimson Samurai Suit: The Crimson Samurai Suit is the ultimate ability of the Crimson Eyes, it takes every ability to unlock and even use. The ability begins by creating fire around the user, it then takes shape and turns into what seems to be a Samurai Suit, then the user must kept a clear mind and concentrate on only the opponent, if they don't the suit will disappear and their eyes will bleed. If they can keep focus though, they will be able to fight for 50 seconds before, the armor disappears, the fire after creating the armor, will then create a katana of fire. Once everything is created, the user will move at crazy speeds, and if anything is hit with their Fire Katana, it will burn until it is reduced to ash or the Crimson Suit, deactivates. Itachi, once created a superior version of the Crimson Samurai Suit, called the Sacred Samurai Suit where his suit and katana were the Sacred Flame, instead of the normal flame. All the abilites, are the same though.
Weaknesses
When Itachi uses the Crimson Eyes excessively, his eyes will begin to bleed and if he keeps uses moves, his eyes can face serious and lasting damage. Each ability, he unlocks with the eyes, the more strain, it takes on his eyes. His first ability has little to no strain on his eyes, his Sacred Flame ability after a few uses will make his eyes begin to bleed, and finally the Crimson Samuai Suit, will make his eyes bleed if he fails to use it correctly, for a few minutes.