Three Kingdoms: I Transmigrated and Became Cao Cao's Eldest Legitimate Son

When he woke up, Zhang Zhi discovered that he had transmigrated into Cao Ang, and not just that: he had arrived on the very night Cao Cao's forces were defeated at Wancheng. He had narrowly survived, but Zhang Xiu was waiting for him. How would he become one of Zhang Xiu's most honored guests, ease the tension between himself and Cao Cao, and help Cao Cao unify the north?