The Three Kingdoms: Rule the World with Sign-In Rewards

Liu Yu transmigrates to the Three Kingdoms era. With the help of a System that lets him summon people by signing in, he unites the Three Kingdoms and dominates the world... Just as Liu Yu is filled with worry, a mechanical voice suddenly sounds in his mind: "Sign-In System successfully bound. Host may sign in once per day to gain a chance to summon historical figures, troops, and other special items." Liu Yu is stunned, then overjoyed. Isn't this the kind of golden finger you always see in novels? He never expected to get one himself. (Warning: Don't think too hard while reading...)