 In that storyline, Superman was coming to terms with the death of his adoptive father; he was also dealing with 100,000 Kryptonians now living on Earth, which he had released from the bottled cities on Brainiac's ship (the same ship that contained the lost Kryptonian city of Kandor).At the end of the fourth issue of the arc, a new Nightwing and Flamebird appear in Superman's Fortress of Solitude to stop two of Zod's followers (who were living in Kandor) from releasing the Kryptonian General from his Phantom Zone imprisonment.While guarding the projector in order to prevent any Zod loyalists from freeing him from the Phantom Zone, both Flamebird and Nightwing exhibit powers that are not inherent to normal Kryptonians.