FF7 - The Cursed Ring and Contain Materia 

You only get the Cursed Ring accessory before Mideel gets destroyed, either with Tifa or Cid as the party leader by finding a beat up old key and telling the truth in the weapons shop. The other cursed Ring is stolen from Ultimate WEAPON when it attacks Mideel though it flies away pretty quickly.
The Cursed Ring increases the stats on the wearer but puts Death Sentence status as well, which can be countered with chained Odin - Added Effect Materia.
The Contain Materia is can be gotten from the white Chocobo at anytime, as long as you have Mimett Greens and scratch it behind the ears.