Tseng closed the door to Sephiroth's apartment behind him. He had patiently listened to the Turk explaining the situation, that Genesis was missing, and, finally, what had happened to Angeal, and how. He had been looking out the window into Midgar's night sky the whole time without interrupting or showing any physical motion.
Finally, Tseng had ended his report and his final inquiry of "Do you have any further questions?" went unanswered. So Tseng withdrew and left Sephiroth to himself. Tseng knew Sephiroth well enough to know that his complete lack of a response in no way meant that he was unaffected by what he heard. But Tseng did not know what to do or say to comfort him. Or perhaps he knew, but was reluctant to act upon this knowledge. Sephiroth could be fairly intimidating, even when he did not actually do anything. His demeanor could easily suppress a person's natural behavior, to the point where Tseng could not even express his condolences in fear that his words could trigger something undesirable. It was better not to say anything at all, or so he thought. It was true that Sephiroth had little patience for empty chatter, but even he could use a kind word or a hug at times. Tseng leaned against the door, exhaling deeply, and closed his eyes for a few seconds. He retained a calm demeanor on the outside, but on the inside, his mind was racing.
No one could tell at this point how Sephiroth would act from now on. If Sephiroth was to become inoperational for prolonged amount of time and word about it was to get out, Anti-Shinra factions like Avalanche or Wutai could come to greater strength than before. They did not need to fear the power of Shinra's SOLDIERs 1st class anymore, as Angeal and Genesis had been pronounced dead, and Zack was far away from reaching his peak as a 1st class SOLDIER, or being able to step in for the deceased SOLDIER members. They needed Sephiroth.
Angeal was not coming back. Genesis had betrayed Shinra. There were no other 1st class SOLDIERs left aside from Zack and Sephiroth. It was a disaster. Shinra had to do their best to keep these news from getting out to the public. Tseng opened his eyes. Zack would be vital to achieve this. They could not rely on Sephiroth at this time, so Zack would have to pull himself together. He pushed himself away from the door. He would need all the resolve he could possibly muster in order to do the thing he feared the most.