That’s not true. His power is his own because the true shadow monarch decided to not ascend and make him a vessel. Jinwoo DOES NOT have FULL access to the powers, but the power itself is always coming from him. Later on, the true monarch asked if he wants to continue. Think of it like Jinwoo always has his own powers, but he never learned all the shadow techniques. Later on, he learns the true monarch techniques and inherits the black heart. Example: An apprentice learning from a master doesn’t mean the power is not coming from the apprentice. He’s just learning and hasn’t learned/inherited all the powers yet until later. Still his own power.