The Forbidden Visual Jutsu

Face to face with a genjutsu Itachi, Danzo freezes Sasuke just as the young Uchiha lunges to impale him, dismissing the illusion as feeble next to Itachi's Tsukuyomi. A cursed seal Danzo planted earlier while gripping Sasuke's throat starts spreading across his body, but Sasuke summons a full Susanoo whose chakra burns the seal away. Danzo counters with a compressed sphere of wind that the Susanoo shrugs off, then Sasuke shapes a bow and looses an arrow. Though seemingly run through, Danzo reappears beside the shaft unharmed.

Madara recognises the trick as Izanagi, an Uchiha forbidden genjutsu that blurs illusion and reality to turn a fatal wound into something that never happened. Each time Sasuke strikes, Danzo escapes, but Karin notices Sharingan eyes closing one by one along his right arm. She realises that once all ten seal shut, his invulnerability ends, only to learn Sasuke already understood this and has been deliberately forcing Danzo to spend eye after eye. Danzo summons the tapir Baku, whose inhalation drags at the Susanoo, and pairs it with wind waves, but Sasuke feeds Baku a great fireball to drive it off. The exchanges continue until only two eyes remain, and the two finally charge one another with blades drawn.

Madara deduces that Danzo's Wood Release means Orochimaru grafted Hashirama Senju's cells into him, which is what lets him bear many Sharingan and wield Izanagi despite not being an Uchiha. He also grasps that the First Hokage's cells combined with the Sharingan could let Danzo control a tailed beast, making the capture of Naruto and the Nine-Tails one of the old man's true aims.