Natsu is pushed to his limits by Zero’s overwhelming power. In a pivotal moment, Jellal Fernandes—regaining some of his memories—steps in to help Natsu by providing the Flame of Rebuke . This golden flame allows Natsu to enter "Dragon Force," giving him the strength to finally overpower Zero with his Crimson Lotus: Exploding Flame Blade .

Fairy Tail Episode 66, titled serves as the explosive climax to the Oración Seis arc. In the English dub, this episode features Natsu’s desperate final stand against Zero, the guild master of the Oración Seis, while the rest of the Allied Forces work to dismantle the city-sized weapon, Nirvana. Plot Summary & Key Moments

While Natsu fights, the other members of the coalition (including Lucy, Gray, Erza, and Wendy) coordinate a synchronized attack on the six "lacrima" crystals powering Nirvana. They must destroy all six simultaneously to stop the machine's path of destruction.