Synopsis: After transmigrating to the impoverished frontier of Dayan’s northern territory, Liu Yi activates a childhood cartoon System with an oddly out-of-place style. It requires him to create a complete set of illustrations for "King of Blade". While studying diagrams that break down its moves, he discovers a unique martial art that lets him unleash shock waves even with an ordinary iron saber. When the northern tribes invade in force during a bitter winter blizzard, his grandfather Liu Wei dies on the battlefield. The young Liu Yi takes up his military registration and heads for the front, sweeping away scattered cavalry with a three-hit spinning counterattack. Step by step, he grows from an inconspicuous child inside a fortress into a formidable frontier warrior admired by Niu San, a thousand-household commander.
And What the hell is using the childhood animation system to cultivate immortality? The beginning was basically the same, but I didn't watch the rest.