Poe recognizes him the moment he sees him. He doesn't see a figure with a mask–and a black cloak. He sees a boy with dark hair and dark, but bright eyes. He sees the quiet, kind, but rather lonely boy who was his friend. So when he's forced to kneel, Poe mouths off–"So who talks first? You talk first?". He wants Ben to say something–anything. Of course, Ben–Kylo–whoever he is–says nothing. Poe wants so badly to believe that Ben isn't gone, that's he's still there inside of the man who now calls himself Kylo Ren. Poe has to believe that–otherwise not only is the boy man he cares about be dead-but he knows if that's the case, he himself will be dead as well.
Poe thinks he can survive the torture–that is until Ben himself shows up. The torture he's already endured, the murder of Lor San Tekka and the rest of the villagers, losing BB-8, all of it has weakened him. He's so tired, but he can't give up. He knows this; so he tries to focus on the past– on the good memories. He thinks of flying, the wind in his hair, the view of the world from above him. He thinks of his mother's laugh and his father's smile–the one he hasn't seen since she met her own demise. He thinks of his squadmates–of Jess and Ello and Snap. He thinks back to the kid boy person that the boy guy man in front of him used to be– and who desperately Poe wants–no needs–to still be in there. He sees the boy friend lover person he used to know. The kid who was quiet while Poe was anything but. The guy who'd shake his head at Poe's jokes, a slight smile always on his face. The friend who comforted Poe when he crashed his first ship. The boy who, surprisingly, kissed Poe first. The boy who used to be so damn scared of failing– of letting people down. Poe thought of that. He didn't think of the last time he saw Ben Solo– how he walked away and Poe just knew he wouldn't see him again. He doesn't let the thoughts of the horrible atrocities Be–Kylo Ren had committed. He just can't think about that. But when Ben–Kylo Ren–whoever the hell he is–gets in his head, all he feels is pain. He feels like screaming–like he could die at any moment– and a scary thought passes through his mind, What if Ben Solo really is gone?