This royal Signet Ring (Sindel's Signet Ring) with the MK dragon symbol belonged to Queen Sindel of Edenia. It made its debut as one of the items, especially important ones within the Konquest mode of Mortal Kombat: Deception.
It is said to inspire any army. Queen Sindel used to have this beautiful and legendary golden ring of Edenian design until it was lost during Shao Kahn's initial invasion of Edenia. Princess Kitana sent the supposed "Champions of the Elder Gods" named Shujinko to find her mother's signet ring and bring it back to her so she can use it to inspire her troops and lead them into battle against Shao Kahn's militia. However, if you do not return the ring to Kitana quickly, it will get stolen by an unknown person.