The duel on Atch-To was a three-way duel in which Finn and Rey teamed up against Kylo Ren, and later Jar Jar Binks, now revealed to be Darth Jar Jar.
Having awakened in the Force, Rey was able to build her own lightsaber. As a result, she allowed Finn to keep his weapon.
The Duel Edit
Kylo Ren ignited his lightsaber. Rey, now with her weapon, and Finn with Anakin's lightsaber, began an intense duel. Although Ren held his own, he was actually on the defensive throughout the clash. Soon after the fight started, famous popstar Katy Perry quickly intercepted them. She began to sing, and, although Ren was skeptical at first, he allowed it. Just then, fellow star Rebecca Black showed up and asked Katy if they should sing something terrible to thrown Ren off balance. Katy tried singing "Roar," but gave up when it didn't work and Ren was able to ignore the distraction. Katy was agitated, as her other songs were too good. Rebecca winked at her and proceeded to sing "Friday," torturing Ren and allowing Finn to cut him down. Just as the four relished their victory, Rey reminded them that Supreme Leader Snoke was still on the grounds.
Darth Jar Jar IntervenesEdit
A moment later, Jar Jar Binks arrived to check on Kylo Ren. When he saw Ren had been killed, and saw the blood in his ears, he picked up on the fact that Finn, Rey, Perry, and Black were all responsible. He revealed himself to be Darth Jar Jar and revealed that Snoke was a small alien under the Gungan's mind control, magnified by hologram. As Finn and Rey prepared to take on Darth Jar Jar, the popstars left. After the two defeated Darth Jar Jar, they took off with Snoke, who was terrified.
Shortly afterwards, the quintet (Rey, Finn, Perry, Black, and Snoke) ran into Han Solo, who revealed that he had been alive the entire time. When Rey asked how that was possible, Han insisted that Ren had stabbed him in the wrong place, causing his wound to cauterize. Finn also explained to Han who Snoke truly was.
With that, the First Order-Resistance conflict came to a quick end.