Mikasa Extra Sheet+Constant Effects+Uncanny Dodge

You gain the ability to react to danger before her senses would normally allow you to do so. You cannot be caught flat-footed, nor do you lose your Dex bonus to AC if the attacker is invisible. You still lose your Dexterity bonus to AC if immobilized. You can still lose your Dexterity bonus to AC if an opponent successfully uses the feint action against you.