Darth Vader tracks down Doctor Aphra, a former collaborator he had previously attempted to kill. Having survived and feigned her demise, Aphra reenters Vader’s life. With her help, the Dark Lord of the Sith acquire the Zaly Shield, also referred to as the Kyberite shield. This shield aids Vader in channeling his Force powers more effectively, which had become erratic due to a Force Wave.
From – Star Wars: Darth Vader Vol. 1 #35







