MONOCHROME

Here's an improved synopsis that incorporates your requirements: "The Demon King, consumed with anticipation for the arrival of his firstborn, is devastated when his beloved wife dies shortly after giving birth to a perfectly healthy son. Left to raise the child alone, he dedicates himself to training the boy, molding him into a powerful warrior worthy of inheriting the throne. Years later, Yagura, a former vigilante, has finally retired to pursue a life of peace. However, his tranquility is shattered when he becomes ensnared in a treacherous survival game with far-reaching consequences. Forced out of retirement, Yagura must now assemble and train a new generation of heroes to protect his city. But will answering the call of heroism truly be worth the price? Read MONOCHROME on capitulos.cloud completely free and without intrusive ads." Read the MANHWA (MONOCROMÁTICO, MONOCROMO, MONOCHROME: Shades of Gray, 모노크롬, モノクローム, 单色) online at Capitulos.Cloud completely free and without ads, with the latest chapters updated.