Black Mask had been building up his gang for some time now. He was finally ready to do what no villian has done so far: blow up Gotham City. Sionis ransomed with the GCPD, but they didn't have enough to pay. As Sionis was about to use his super weapon, Batman came in an beat up Black Mask and took him to the GCPD for questioning. While in the GCPD building, Black Mask's gang used knock-out gas to knock out all of the officers in the building. What they didn't expect was Batgirl and Robin to be there and stop him. The two sidekicks tried to keep Black Mask's crew out of the building, but they got in anyway and released Sionis. On his helicopter, Sionis prepared to fire his bomb when Batgirl and Robin return. However, they were too late and he had the bomb rigged to blow in five seconds. When the counter hit 0, nothing happened. They took Sionis back to the GCPD and found that Batman had defused the bomb in time.
- Taser Gun
- 4 Appearances of Roman Sionis (The Batman)
- 3 Images featuring Roman Sionis (The Batman)
- 1 Quotations by or about Roman Sionis (The Batman)
- Character Gallery: Roman Sionis (The Batman)