If you want to read the source material for this specific episode, it covers the following chapters:
"Lord Seventh," Shikamaru communicated via earpiece. "The sensors are picking up strange fluctuations near the old Uchiha district. It’s... residual chakra. Like a tear in the fabric of space." boruto 218
"I have to end this," Kawaki said. "If I send him to a dimension where time doesn't move, Momoshiki can never resurrect." If you want to read the source material
The only hope left is a desperate, last-minute plan: use Kawaki as bait to shrink and trap Isshiki in a sealing cube. residual chakra
In that moment of hesitation, Momoshiki grinned. "A mistake."
Before they could analyze further, a figure emerged from the trees. It was Boruto, drenched and breathless. But his stance was wrong. He was clutching his right eye, and the tell-tale black markings of the Karma were creeping up the side of his face.
Meanwhile, at the entrance of the village, the rain blurred the view of the forests beyond. Shikamaru Nara stood with a squad of Anbu, his expression grim.