Extended ability information.
Eternal Mangekyo Sharingan & Me
A Summary of Magical Delights
Some of you are already familiar with the Sharingan. It's that funny-looking red eye that all Uchiha here possess... at least the ones who still have their eyes. It looks like this. At its most basic state, it enables the user to see chakra (that beautiful glowy life energy that ninja manipulate to use ninjutsu), perceive movement with almost precognitive accuracy, and record everything with photographic memory to the point that the user can then perfectly mimic whatever action is seen. This means anyone with a Sharingan can copy anyone's attack if they see it, provided there isn't some magical or genetic requirement.
That's just the beginning. Welcome to the world of shounen villainry.
There is a second evolution that comes about when someone with a Sharingan kills someone they love. This is called the Mangekyo Sharingan. Each Mangekyo is unique and special in its own little ways. Madara's Mangekyo looked like this... before he ruined it and went blind. See, the Mangekyo "loses its light" with overuse, and Madara has issues with self control. Madara's Mangekyo was the most powerful eye jutsu of his time, enabling him to conquer many peoples. But in exchange he became crippled and useless after only a few years in power.
Lucky for Madara, he had a little brother, and little Uchiha brothers make excellent spare eyes. Izuna, too, had his own Mangekyo, and it was even in good working order. A very messy surgery was performed, and Madara tore out Izuna's eyes then transplanted them to himself. Their powers combined, and so did their super special eye patterns. This became the first ever Eternal Mangekyo Sharingan. As the name implies, it's a Mangekyo that can be used again and again without ever going blind. One way or another, this also resulted in granting Madara immortality.
Madara has terrible luck so he ended up losing one of his eyes yet again in his battle against Hashirama eighty years ago. On the bright side, he at least survived the battle. But this halved his power, and up until this moment, he was still operating in his weakened state. Yeah. Now he has his left eye back, restoring him to the height of his power.
Enough with the history lessons. Wondering what it all means for you? Well, let's move on to what Madara can actually do while at full power (and also what happens when he's nerfed).
Amaterasu [wiki] • Madara can set you on fire just by looking at you. Also these black flames are as hot as the sun. Also nothing will extinguish them, and they'll burn for seven days and nights unless Madara himself actually withdraws them. Of course if you toss off your burning clothes before they reach your skin, you have a good chance of saving yourself. Madara cannot use this ability outside Facility 3. The Biodome is happy.
Tsukuyomi [wiki] • This jutsu is the reason you should probably never look Madara in the eye. To activate it, all he has to do is meet your gaze. From there, he's in your head. He can twist all of your memories and use them against you, or make you experience all new nightmares of his own invention. This is an illusion that goes beyond illusion. He can make you perceive a second as a hundred years, and fill all of that space with endless tortures and pain that feels completely real. Even the most skilled psychics would have trouble with this one. It's stated that only someone from his bloodline could break out of Tsukuyomi using their own Sharingan. Using this also physically weakens the victim, usually putting them in a coma for a few days. It's the ultimate mindfuck. Outside of Facility 3, it's actually possible to break out of this with enough willpower, and he can only use it a couple times per week. If you're blind? You're always safe.
Mind Control • This appears to be a sub-technique related to Tsukuyomi, as mentioned in Madara's eccentric Moon's Eye Plan, which involves projecting a gigantic Sharingan onto the moon so he can cast something he uncreatively calls Infinite Tsukuyomi on the entire planet and RULE THE WORLD! Tsukuyomi appears to open a gateway into the mind that makes it fresh for manipulating, which makes sense since it gives him the ability to control someone's senses and believe in the world he creates in their mind. It also seems to be how he controls the Tailed Beasts, and Kyuubi in particular at several points in history. It's implied that he also used this at one point to control the Fourth Mizukage. Poor kid. Madara is especially gleeful because the Doctors have granted him the ability to use this again, but only in Facility 3.
Izanagi [wiki] • The most forbidden of forbidden techniques. This jutsu bends reality itself. It's not an illusion. It's an undo button. Did you just manage to actually impale Madara through the chest without letting him get away? Is his heart now speared on your blade, his blood coating your hands? Are you actually... actually victorious in the battle against great evil? NO. You aren't. Because he just completely reversed that. It's the godmode of all godmodes. It's bending reality to his whim. It's making an illusion, whatever Madara wishes, come to life. But every time he uses it, it completely ruins the eye he used to cast it. Completely. And that's why you'll probably never see him use it, since death is not a permanent thing here. I'm mentioning it anyway because... who knows what the future holds. Either way, he can't use it outside Facility 3.
Teleportation [wiki] • I know, why's there no fancy name for this one? What a ripoff. This is the jutsu you see Madara use all the time, because he is both lazy and loves to show off. Most ninja use a technique that looks similar, but they're really just moving very fast. Madara himself slips in and out of existence at will. This can be his entire body or just parts of it, which makes it virtually impossible to land an attack on him unless you catch him by surprise. It's best to operate on the assumption that Madara is not actually solid at any moment unless he is physically interacting with something. He can appear anywhere in an instant and be gone just as quick. Normally he can teleport himself and others into an entirely different dimension, but he obviously can't do that here. He can teleport around any of the Facilities, although there's a slight delay when used outside of Facility 3.
Regeneration • This may or may not actually be a Sharingan technique, but hell, I'll mention it here anyway since canon is so painfully unclear. Madara has displayed the ability to tear off his limbs and regenerate them. Until this is explained, I consider this accelerated healing to be related to his supposed eternal youth. His regeneration is considerably slowed outside Facility 3, and what normally takes him minutes to regenerate could take several days in Facility 1.
Now that we've covered all that... Any questions?