Essence of theEternal Mangekyō Sharingan

You can put anyone through an illusion by meeting with their eyes. Yes, this version works for anyone. You can manipulate all of their senses, and even control their actions or look through and manipulate their memories.

When using your eyes (or eye) at full power, you can completely control non-human beings, such as Tailed Beasts or similar.

You can also focus any mental interference ability you have through your eyesight now.

As a possessor of the Eternal Mangekyō Sharingan, you possess all the abilities of the Mangekyō Sharingan on an even higher level. You possess most canon Mangekyō abilities:

You possess the ability to create black flames, the Amaterasu, also called Hinokagutsuchi. These flames are created on whatever you are looking at, and are very difficult to avoid. This ability is able to burn anything, including other flames. These flames cannot be extinguished through normal means.

You possess the ability of Kagustuchi, the power to manipulate any flame by manifesting shape transformation in them. By combining with the former ability, you can control your Amaterasu.

You possess the ability to cast an illusion that can't be escaped without the Sharingan, the Tsukuyomi. By making contact with someone, you might trap them into an illusion of your own making. You can manipulate the target's perception of time, possibly making them experience lifetimes in a second. This illusion can't be broken unless the user has a Sharingan that is at least one level lower than yours. So if you have the Eternal Mangekyō Sharingan, the opponent would need at least a Mangekyō to break themselves from it.

You can cast a subtle illusion called Kotoamatsukami, a form of mental control that manipulates someone by giving them false experiences and making them think they are doing whatever you commanded out of their own will. This can even override commands from other abilities. This ability can be used without eye contact. You don't have a cooldown after using this.

You possess the Kamui. A space-time technique that allows you to warp to a dimension of your design. You can use the long distance version to warp a target into the dimension, or the close range version to warp yourself or something you are touching. This also grants you a form of intangibility by warping your body into the Kamui dimension whenever you are attacked. You can teleport to essentially any place in your local multiverse by using the Kamui, although leaving your universe will take a lot of you. Like a real lot.

You gain Shin's Object Manipulation Technique. You can mark objects with a seal that you possess in your palm, and telekinetically control them. Your fine control over objects is just like your own fingers.

You possess the ability of the Engraved Tsukuyomi: By reflecting your Sharingan on the moon, you can brand those caught in the light with your Sharingan. With this, you'll be able to use the Yachihoko, controlling the mind and chakra of anyone branded by your Sharingan.

You possess the ability known as Ōhirume. This allows you to create black spheres that resemble and act like black holes, which have a gravitational pull that you can freely and selectively manipulate. Yours lack the weaknesses of Sarada's.

You can use the Izanagi. Whenever activated, you can turn anything that happened in the following fifteen seconds into an illusion, essentially allowing you to reject events. You won't lose an eye whenever you activate the Izanagi, instead being limited to the base form of your Sharingan for two days instead.

You can use the Izanami. It's a form of illusion that traps the target into a mental time loop until they 'accept their fate.' You won't lose an eye whenever you activate the Izanagi, instead being limited to the base form of your Sharingan for two days instead.

You are able to use the Transcription Seal: The ability to program your or another person's Sharingan to automatically activate a particular technique by creating specific triggers. For example, you could make it so that the Izanagi would activate after you died to revive you.

With time and research, you can create your own unique Mangekyō abilities as long as they are around the same level as the canon ones. You can create as many as you want.

You possess the power of Susano'o. The power of manifesting an ethereal armor around yourself. By default, yours is as strong and advanced as Edo Madara's, having all normal Susano'o abilities. You can freely customize how it looks and its color.

You can equip any weapon you have to it, making a giant ethereal version of it when you activate your Susano'o. By default, you start with the Yata Mirror (which can reflect any attack by manipulating the five elements) and the Totsuka Blade (Which can seal anything it stabbed into a world of drunken dreams.)

You can channel any Mangekyō ability you have through your Susano'o, allowing you to create your own unique weaponry. For example, blades made of Amaterasu fire, Shurikens that warp whatever it cuts to the Kamui dimension, or a sword made of Ōhirume matter.

You can use the ability of Majestic Attire to wrap your Susano'o around a being, considerably increasing it's strength.

Optionally, you might gain the ability to wrap your Susano'o around your own body, making it sort of a fake Chakra Mode. Like with the Jinchūriki, the power of your Perfect Susano'o increases by dozens of times due to your power being channeled over a smaller size.

You can pass the Sharingan to your children. They will naturally unlock the Mangekyō stage through training without the need for trauma, and won't get blind from overusing it. You can choose which children you want to have it, and which you don't.

Optionally, you gain a pool of Chakra comparable to EMS Sasuke in the Fourth Shinobi War, before he got the Six Paths Power.

Optionally, if you get strong enough you can naturally unlock the Tomoe Rinnegan, a dōjutsu that possesses the powers of both the Eternal Mangekyō Sharingan and the normal Rinnegan. You will be able to choose it's color, and will be able to craft unique abilities on the level of the Rinnegan unique abilities instead of just the Mangekyō.