Echoes of the Imperial Sun

The Premise:
A brilliant strategist dies defending his sworn brotherhood in a bloody rebellion, only to wake up five years later in the body of a frail, low-ranking noble's son.

The Hook:
Seeking a quiet life, his plans are ruined when his former best friend-now the brooding, feared Crown Prince-notices the "frail noble" using military strategies that only his deceased soulmate ever knew. The prince becomes obsessed with uncovering the noble's true identity, while the strategist must navigate the very court that betrayed him.

Core Tropes:
Reincarnation/identity reveal, slow-burn angst, shared history, political chess match.

summary:
Reborn five years after being betrayed and killed at the Pass of the Red River, former General Min Taehyung tries to live a peaceful, low-profile life in the Southern Province as the sickly clerk Kim Taehyung. His plans crumble when Crown Prince Jeon Jungkook personally arrives to audit missing military grain. During the inspection, Taehyung's razor-sharp intellect and military posture accidentally draw the Prince's intense scrutiny. Though Taehyung manages to hide his true identity behind his physical frailty, his unmatched knowledge of northern supply routes sparks Jungkook's suspicion, leading the Crown Prince to draft him into the imperial escort bound for the capital.