Switch My Heir? Now You'll Pay for It!

The Emperor and Empress lost their first son soon after he was born. So the Empress would not grieve, the Emperor took in an abandoned child from among the common people, Rowan, and gave him to her to raise as her own. That son grew up as the presumed heir. The Emperor dies and wakes again on the night before the crown prince is to be named. He moves at once. He gathers the evidence, strips Rowan of his standing as an adopted son, names his own blood son Arthur, and puts down the factions around the Empress and the Empress Dowager. Everything he owed Arthur in the life before, he settles in one go.