What devil fruit did Gecko Moria eat?
Kage Kage no Mi Moria ate the Kage Kage no Mi, a Paramecia-type Devil Fruit that allows him to manifest and control shadows as physical entities. Moria can manifest his own shadow and have it fight in his place, as well as split his shadow into a number of bat-like creatures that he can use to swarm his enemy.
What is Gecko Moria power?
In addition to his considerable resistance to damage and fatigue, Moria possesses impressive willpower; using Shadows Asgard, he managed to sustain 1000 shadows within his body, though it did exert him greatly. His willpower also prevented him from being knocked out by Luffys Conquerors Haki at Marineford.
Can Luffy use nightmare again?
Nightmare Luffy has never been used again after that arc.