Naruto Shippuden the Movie: The Lost Tower

Mukade shatters the seal on the Ryūmyaku, a powerful chakra leyline hidden beneath Loran. This releases an overwhelming burst of light that engulfs Naruto and Yamato, propelling them twenty years into the past, before the series began, to the era when Minato Namikaze was alive.

The seal on the Ryūmyaku was placed by Minato, hinting at his connection to the event.

The Ryūmyaku is a deep, world-spanning chakra leyline hidden beneath the land of Loran. It contains enormous dormant energy. Mukade wants to awaken and seize this power to control the Puppet Ninja Forces and dominate the region.

Mukade traveled even earlier in history than Naruto, twenty years prior, and renamed himself Anrokuzan. In the past, he becomes a minister who has already killed Sāra's mother, Sēramu, and seized control of Loran.

The timeline notes mention Mukade traveling "even earlier," revealing his identity shift.

Minato erases the memories of Naruto, Yamato, and others to preserve the timeline. If they remembered their time in the past, it could create paradoxes or alter history, potentially changing events that were meant to happen.

The mission involves preventing changes to history throughout the film.

Sāra's daughter reveals that her mother was entrusted with an ancient chakra blade by a "Hero in a Dream", which is Naruto himself, traveling back in time. This explains why Naruto instinctively reaches for a familiar blade at the end, only to find it missing.

Naruto wields the chakra blade throughout the past battle.

Naruto and Minato combine their chakra in a regenerative surge, pooling their massive combined power into a single technique. This creates the legendary Super Rasengan, which overwhelms Anrokuzan's colossal puppet and shatters its defenses.

Sāra's memories of her mother Sēramu's lullaby begin to stir during the conflict, anchoring her bond with Naruto and strengthening her resolve. The lullaby represents her heritage and motivation to resist Anrokuzan.

Sēramu's death by Anrokuzan sets the emotional stakes for Sāra.

After defeating Anrokuzan, Sāra is pulled to safety by Yamato and Kakashi alongside Naruto. However, Minato erases her memories along with everyone else's, so she returns to the present unaware of the connection, though her daughter later carries forward the legacy of the chakra blade.

Naruto instinctively reaches for the chakra blade he wielded in the past, having formed a muscle memory of the weapon. However, it's not in the present because he never actually possessed it, it existed only in the timeline where he was the "Hero in a Dream."

The blade was given to Sāra in the past, not brought to the present.

Anrokuzan uses the Ryūmyaku's power to create the Puppet Ninja Forces, an army of massive mechanical puppets controlled by chakra. He even assembles a colossal defensive puppet from tower parts to overwhelm the defenders.

After learning that Anrokuzan killed Sāra's mother and now threatens her kingdom, Naruto makes a vow to protect Sāra. This stems from his nature as a protector and his emotional connection to her despite meeting her in a different time.