Davros's Time Ring
From Tardis Wiki, the free Doctor Who reference
A "sacred" Time Ring was stolen from Gallifrey by Davros, who took it back to 2254 Skaro, where the Time Lords sent the Seventh Doctor to retrieve it before the scientist could use it to do any serious damage. After the Doctor succeeding in stopping Davros (killing the current Dalek Emperor in the process), the Time Lords froze Davros in time as punishment. (GAME: Dalek Attack)