Battle Through the Heavens: Starting as a Sweeper and Becoming Invincible Through Sign-in

Xiao Chen transmigrated to the world of Battle Through the Heavens, a world of Dou Qi, where young geniuses such as Xiao Yan, Xiao Xun'er, and Nalan Yanran emerged.
Xiao Chen was just a janitor in the Xiao family's Dou Qi Pavilion, and his fate was only officially changed when the sign-in system was activated.
At the Dou Qi Pavilion, he signed up for the Pure Lotus Demon Flame, which ranked third on the Strange Flame Ranking!
Beside Xiao Xun'er, he signed up for the Xuan-rank advanced cultivation technique, the Flame-Making Technique!
He signed for three Qi Gathering Pills from Nalan Yanran!
……
He can sign in to find treasures that others can't.
He can sign in for the treasures that others have.
He can sign in anywhere on the Dou Qi Continent as long as he wants.