Comprehensive Comic: Start with a Substitute

My name is Bai Luo, and I have traveled through time. Mother Cecilia, father Siegfried, and an older sister named Siren, and two younger sisters, one named Bianca and one named Kiana. They are very strong, one is a dead otaku with a golden cross in her pupils, one is the strongest Valkyrie in the world, and the other is the Herrscher of Fire who can shine and generate heat. But that doesn't mean he's safe. There are many crises in this world. There are the Red Apostles who devour humans, the endlessly killing Honkai Beasts, angels and demons, Academy City's superpowers, demon special zones, and even... Fortunately, he has a system that allows him to become stronger by completing tasks. The world's most famous cartoonist, St. Freya's strongest male teacher, the savior of vampires, the strongest exchange student in Academy City, the uncrowned king of Genkami Island, and the envoy of nuclear peace in Fuyuki City... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.