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Chu Zhitian was no stranger to the Zhi Ge Courtyard, having visited a few times before.
Moreover, he often corresponded with Prince Ying, Chu Mingrui, through letters.
The letters not only discussed the art of war and military strategies but also the movements of the Northern Territory army, the purpose behind each maneuver, and encounters with the Da Meng's Stepping Cloud Iron Cavalry.
The subtle changes and choices of thoughts were meticulously written down and sent to Chu Zhiyuan.
The two even used an encrypted writing method.
The letter had to be rewritten using encryption techniques, making it indecipherable to outsiders.
Chu Zhiyuan would receive Chu Mingrui's letters every few days, jokingly saying they were more frequent than family letters.
Chu Zhiyuan would also promptly reply.
Both had deep knowledge of the art of war, military formations, and the Stepping Cloud Iron Cavalry, benefiting from their exchanges.
Chu Zhiyuan discerned Chu Mingrui's intentions.
