Sky Prison signed in for 20 years, I am invincible in the world

Introduction: Chu Xuan traveled through the fantasy world and became the deposed prince of the Great Xia Dynasty.At the beginning, he was thrown into the dungeon, but fortunately, he awakened the sign-in system.As long as he signs in at a special location, he can get rich rewards. "Ding, you signed in successfully, you got the Ice Holy Body!" "Ding, you signed in successfully, you got the Nine Dragons Pulling the Coffin!" "Ding, you signed in successfully, you got the Dragon Elephant Suppressing Prison Force!" Many years later, when Chu Xuan walked out of the prison, he found that he was already invincible in the world!