While many titans possess physical specializations—the size or the Armored’s plating—the Attack Titan’s true strength is metaphysical.
Sooo,since the attack titan "always fights for it's freedom" - Facebook 9 : Attack Titan
: Its holders are often consumed by an intense desire for rebellion. This isn't just a personality trait but a fundamental aspect of the titan's nature, described as "moving forward until the end". 9 : Attack Titan