Complex sentence: The series follows "Jack", an unnamed samurai sent to a dystopian future ruled by the tyrannical shape-shifting demon Aku, in his singular quest to travel back in time and defeat Aku before he can take over the world.
Split into simpler sentences: The series follows "Jack", an unnamed samurai sent through time to a dystopian future ruled by the tyrannical shape-shifting demon Aku. Jack quests to travel back in time and defeat Aku before he can take over the world.