That certainly sounds like Donnie knows, but Sephiroth really couldn't say for sure. He's not particularly thrilled by the thought of talking to Donnie about it either. Whether or not Donnie knows, Sephiroth is sure he would not get a warm reception. That doesn't mean he won't try, but first he'll probably try to determine if that's really who he should talk to.

"How long do you plan on keeping him here?" he asks.

Part of him thinks it's actually not necessarily a bad idea to confine a zombie and observe it. They need knowledge in this situation. But he is highly doubtful that leaving it to a teenager is the best option.