Arc 10The King of Honkai
Feng Chen returned to his companions and entered the Quantum Sea with Bianca, where he uncovered a plot to provoke war and learned that Otto intended to bring Honkai into the world. After becoming the King of Honkai and defeating the Tenth Herrscher, Feng Chen and Sirin left for another world, where he rescued a young Sirin from an experiment.
- Feng Chen left the past behind, returned to his apartment, and gave Otto the final quantum computer terminal in exchange for the Sirin Project data and a larger villa.
- Feng Chen struggled with the danger of his uncontrollable Honkai Energy, but Bianca stopped him from taking his own life, and Rita learned the truth about his origins and promised to protect those he cared about.
- Feng Chen entered the Quantum Sea with Bianca and landed in a world where humans and Honkai coexisted, then joined Sirin, Rita, and Bella on missions to enforce their agreement.
- Feng Chen rescued Bronya and Seele from Honkai Beasts, while he and his companions investigated altered Honkai Energy and discovered that someone was provoking conflict between humans and Honkai.
- Feng Chen confronted Otto in Siberia, where Otto revealed his plan to bring Honkai into the world and called Feng Chen the first vessel infected by Honkai Energy.
- Sirin gathered the Herrscher gems and became armor for the key and lock, which chose Feng Chen as Finality and made him the King of Honkai.
- Feng Chen attacked the Tenth Herrscher with human weapons and the Mimicry Divine Key, White Flower, until Sirin appeared and helped him leave the world with Bianca.
- Feng Chen arrived in another world, canceled Sirin's experiment, and took her from the laboratory before noticing Seele Vollerei on the Valkyrie roster.