Ione's large eyes and small voice help her maintain her illusion of being an innocent witness to the crimes found in the deeper levels of Coruscant. Few would suspect her as a thief or accomplice to murder. Ione was a partner in crime to the nimble Cassie Cryar. When the two hoods managed to get a hold of a stolen Jedi lightsaber, they desperately tried to avoid the law.
Ione Marcy was Cassie's partner in crime. Ione easily deceived the law enforcement authorities into thinking she knew nothing of Cassie's involvement.
The crowded city-planet is home to countless criminals who can lose themselves in the bustle of the lower levels, including Ione Marcy. The law, however, eventually did catch up to her.
It was Ahsoka Tano's lightsaber that Cassie Cryar and Ione Marcy used to murder Coruscant criminal Nack Movers. Ahsoka was determined to reacquire her weapon from the underworld.