Sasuke is shown using his eternal mangekyou sharingaan in manga chapter #574.
In this chapter he uses his new Susanoo to obliterate a small platoon of white zetsu within seconds. It is also described he was now able to see the darkness in souls of his enemy.
sasuke was 15 when he took itachi's eyes the eyes of mangekyo sharingan he was 20 when he got eternal sharingan he was 3 in the accounts of meeting sakura and naruto every girl likes sasuke because of his sexy emo power this is your infomation.
No one really knows the true purpose because its a Uchiha clan secret
No, Sasuke has now obtained the Eternal Mangekyo Sharingan, by transplanting his dead brother Itachi's eyes. One ability of the Eternal form is that the user will never suffer blindness from overuse.
The Eternal Mangekyou sharingan is the combination of two Mangekyou sharingans. It gives the user a great power, and the user is able to use the double the amount. The user can use all the power of the Mangekyou sharingan, without worring about blindness. This doujutsu is able to tame the Kyubi but there's only one person that possesses this eye, Madara Uchiha. When he took his brother's eyes, he found a new light that will never fade from his eyes, giving to him the eternal life. In Naruto Shippuden chapter 488, Sasuke Uchiha had an operation that gave him the eternal Mangekyou Sharingan, making him the second one to posess this eye.
sasuke dose activate Mangekyo, im assuming you dont read the manga or up to date in anime. i can tell you how it's just a massive spoiler but whatever. Sasuke Activated the Mangekyo after itachi's death - Itachi being the one who was of value to have died.