Transported to feudal Japan alongside other Gotham City villains by Gorilla Grodd's Quake Engine, Slade Wilson operates as the mercenary Deathstroke. He seizes power as a daimyo, ruling the Natsu region. Like the other transported villains who usurp local warlords, Deathstroke seeks to conquer and unify Japan, fueling intense factional conflict.

Reflecting his tactical nature, Deathstroke's mechanized castle transforms into a mobile fortress during the climactic battle at the "Field of Hell." This transformation contributes to a larger convergence where all villain castles merge into a single super robot controlled by the Joker. Initially, Deathstroke forges an alliance with Grodd and Two-Face to secure power converters needed to reactivate the Quake Engine for their return. Grodd later betrays this alliance to pursue his own domination of Japan.

Mobilizing his forces alongside the other villains in the decisive battle, Deathstroke is ultimately defeated by Batman and the Bat-Family. Following the collective downfall of the villains, he is returned to the present era. His role remains defined as a faction leader within the film's context of mechanized feudal warfare.