Arc 12Sky Island and Dark Lightning
Uchiha Xin defeated Enel, claimed Sky Island, and gained the powers of the Rumble-Rumble and Dark-Dark Fruits after fighting Blackbeard. He and Robin reached Fish-Man Island, where Neptune and his family awaited them as Xin sought the next Poneglyph.
- Uchiha Xin found the third Poneglyph in Arabasta, then confronted the Straw Hat Pirates at the harbor and defeated Luffy, Zoro, and Sanji before leaving them alive.
- Uchiha Xin brought Vivi to the Divine Palace, revealed what Robin had learned about the Poneglyphs, and granted Ten-Tails Chakra to Tashigi, Nami, and Vivi as they became his retainers.
- Uchiha Xin took the Divine Palace to Sky Island, where Tashigi, Robin, and Perona repelled Enel’s attacks while Xin defeated and killed Enel.
- Uchiha Xin absorbed Enel’s Rumble-Rumble Fruit and the laws of Sky Island’s Poneglyph and Golden Bell, while Tashigi and Perona subdued Enel’s forces and Gan Fall surrendered the island.
- Uchiha Xin and Robin descended toward the Blue Sea and encountered Blackbeard, whose crew Xin repelled before destroying their ship and overpowering Blackbeard.
- Blackbeard fled, but the system awarded Uchiha Xin the Dark-Dark Fruit, which he fused with the Clear-Clear and Rumble-Rumble abilities into hidden dark lightning.
- Uchiha Xin and Robin traveled toward Fish-Man Island, and Xin sensed a powerful presence in Mary Geoise before deciding to strengthen his Eye of God first.
- Uchiha Xin carried Robin through the deep sea behind an invisible barrier, spotted the Sea Forest Poneglyph, and arrived above Fish-Man Island as Neptune and his sons awaited them.