This cursed seal is used by the Hyūga clan in order to protect their kekkei genkai, the Byakugan. Members of the clan's main house brand members of the clan's branch houses with the cursed seal so that, when they die, their Byakugan will be sealed away, preventing its secrets from being learned by enemies.
Also there is no curse seal for the main family. Therefore it doesn't matter if Hinata and Hanabi are on the same side of the family, because their side doesn't have a curse seal. Only the branch family have curse seals that's why they're the branch family.
It was fully removed when Sasuke used it as a medium to revive Orochimaru's consciousness and body via the Evil Releasing Method. During Sasuke's battle with Itachi Uchiha, he lost the cursed seal, along with Orochimaru (having earlier been absorbed into Sasuke's body), as they were removed with the Sword of Totsuka.
Now another name for the Sharingan is Tengan which means Heaven's Eye, this is most likely cause of the three tomoes it has. Tomoe represent heavens and gods and hence it makes sense for the curse seal with three tomoes to be called the curse seal of heaven. The curse seal gets its name from the design.
No Sasuke does not still have the Curse Mark. When Itachi Used the Tosukuta Blade on Orochimaru it completely removed the Curse Mark sealing, from Sasuke. It was one of the things Itachi wanted to do before he died. No Sasuke does not still have the Curse Mark.
when he had curse seal on him he could fly in version two state. And he got hawk summons which aid him in flying.
Baker's dozen means 13, instead of 12. The tale behind its origin is that a mediaeval law specified the weight of bread loaves, and any baker who supplied less to a customer was in for dire punishment. So bakers would include a thirteenth loaf with each dozen just to be safe.
Specifically, in terms of the “baker's dozen”, if a vendor or other customer were to order a dozen or several dozen loaves of bread from a baker, the baker would give them 13 for every dozen they ordered. This practice eventually made its way into the Worshipful Company of Bakers (London) guild code.
Elena and her three doppelgangers.