Ninja Apocalypse

Hiroshi, Fumitaka's own lieutenant, killed him. Hiroshi used his shapeshifting ability to impersonate Cage and commit the assassination, then framed Cage for the murder to prevent him from becoming Fumitaka's lieutenant.

Earlier in the film, a repeating transmission from Hiroshi hints at a second working elevator, though the message cuts out before coordinates can be shared, establishing his hidden presence.

Hiroshi framed Cage because he wanted to become Fumitaka's lieutenant instead. By framing Cage for the murder, Hiroshi eliminated his rival and positioned himself to take the vacant lieutenant position.

Three witnesses step forward identifying Cage as the assassin immediately after the murder, though their testimony is part of Hiroshi's setup.

Hiroshi killed Fumitaka to keep Cage from becoming Fumitaka's lieutenant. Rather than let Cage rise to the powerful position, Hiroshi used his shapeshifting ability to murder Fumitaka and frame Cage, eliminating both threats in one act.

The elevator Trillion scouted was a decoy set up by the rival clans. Rather than providing an escape route, it dropped the Lost Ninja Clan to the bottom level where hordes of zombies were contained, likely as a trap to eliminate them.

The Siren Clan is an all-female group of clones who initially appeared friendly to lure the survivors into a false sense of security. Their hostile turn was a deliberate ambush strategy to kill or capture the weakened ninjas.

Hiroshi possesses a shapeshifting ability that allows him to physically transform into other people. He used this power to impersonate Cage and commit the assassination of Fumitaka right in front of witnesses, then disappeared before anyone could catch him.

Becker, the rival fire-wielding clan leader, was impressed by Cage's honor and mercy during their fight. When Cage showed mercy rather than killing Becker, it demonstrated the integrity that set Cage apart from the ruthless murderer he was framed as, earning Becker's respect and loyalty.

Trillion was bitten by a zombie while in the bottom level, triggering panic among the survivors. The bite suggests he was infected with the zombie pathogen, though he continues to fight and is later killed by the Siren Clan during the ambush.

Sky sacrificed himself to allow the remaining clan members (Cage, Surge, and Trillion) to reach the working elevator and escape. He held off the zombie horde long enough for the others to board the elevator, giving his life so they could continue their escape.

The peace conference was called to unite the various ninja clans against external threats looming in the post-apocalyptic world. Fumitaka proposed an alliance for survival, but the assassination derailed the conference and plunged the bunker into conflict.

The three witnesses who accused Cage of killing Fumitaka were part of Hiroshi's setup, likely either planted or deceived by his shapeshifting deception. Their testimony was instrumental in turning the other clans against the Lost Ninja Clan.

Surge was poisoned by the Siren Clan during their attack but continued fighting alongside Cage. He was later stabbed by Hiroshi impersonating Cage, but Surge returned with a final act to kill Hiroshi before dying from his combined injuries.