The protagonist of the novel, the special forces soldier, transmigrated and signed a symbiotic contract with the Black Dragon King, Jack. This was a story about transmigration and superpowers. The protagonist transmigrated to another world and became a special forces soldier. In this world, he met the Black Dragon King Jack and signed a symbiotic contract to become his power partner. The Black Dragon King Jack has great power and can control the power of darkness. The protagonist can use various weapons and skills to help the Black Dragon King Jack fight and protect his home. They had experienced many adventures together, experienced each other's growth and changes, and became true partners and friends.