And then on top, he tries to face Riku, loses horribly, and get backed into the railing with fear in his heart which makes way for darkness to pour out and we have our Gargoyle Nightmare.I see him running away from Riku rather than fighting him, he probably causes nightmares to attack Riku on the ground floor of the cathdral, and when Quasimoto holds them back with Phoebus, Riku goes to the top of the tower.