The Eternal Mangekyō Sharingan represents the pinnacle evolution of the Mangekyō Sharingan, which itself is the advanced stage of the Sharingan. This power enhances every aspect of the Sharingan to an exceptional degree, while also unlocking a host of additional abilities that push the boundaries of its potential.
That includes changing your Sharingan shape into a distinct and mesmerizing pinwheel pattern of your choosing.
Summoning and manifesting several stages of the avatar known as Susanoo. This formidable entity can get up to an astounding 250 meters tall and is composed of pure energy. It serves both as an impenetrable shield and an unstoppable weapon, capable of unleashing devastating attacks that could slice an entire mountain range in half.
Lastly, unique techniques exclusive to your Mangekyō eyes, which can be selected within it's own hidden tab beneath the upgrades section.
Your Eternal Mangekyō Sharingan and it's abilities can be used as many times as you wish to, without limitations, adverse effects, or strain. You can freely utilize it as many times as desired, without fear of depletion or negative repercussions.