Character Arc
Tsukasa Shishio is introduced as one of the strongest fighters in the series, a young man once celebrated as the strongest primate high schooler for his extraordinary physical power. After awakening in the petrified world, he initially allies with Senku but soon reveals a starkly different vision for the revived planet. His combination of intelligence and overwhelming strength makes him a formidable presence from the moment he appears.
Tsukasa believes the petrification offers humanity a rare chance to start over without the corruption and inequality of the old world. He intends to revive only the young and pure of heart while destroying the relics and adults of the former civilization, a philosophy that places him in direct opposition to Senku's goal of reviving everyone. This ideological divide transforms him from an ally into the primary antagonist of the early story.
As leader of the Empire of Might, Tsukasa wages a conflict of force against Senku's Kingdom of Science. Despite his ruthlessness, the series gives him sympathetic motivations rooted in his past and his protective love for his younger sister. His arc explores whether might or knowledge should shape the new world, and over time his rigid convictions are challenged by the consequences of his choices.