The protagonist possesses a great degree of intellect or knowledge that they often use to fool other characters or overcome obstacles in creative and unconventional ways. 'Trickster' may also refer to a god or supernatural being specifically known for their mischief who plays a major role in the story.
The empire has turned into the land of the undead due to a spell gone wrong. God summoned heroes from countless worlds to purify the empire and plant new hope. Lee Shin Woo, an ordinary earthling, was also summoned. As an undead, that is.