From the Start, I'm Lightning Feiying, But Why Am I Only Nine?

Li Haotian alters time to save Li You'er, but the effects of changing time on the entire world are immeasurable. Parts of the world's spacetime fall into disorder, and Xu Tingfei is accidentally struck by the backlash of spacetime, sending him to another universe.

In this other universe, Xu Tingfei encounters the Light and Shadow Armors and Super Beasts that never existed in his memories. He isn't afraid of a challenge, though. He believes the Feiying Armor can solve anything.

But there's one problem... Why is he only nine years old?

Looking at his small, soft body, Xu Tingfei can only feel helpless. Fortunately, his energy level doesn't change with his body, and he remains the best person in the world to summon the Feiying Armor.

After Xu Tingfei intervenes time and again, Lufa awakens earlier than expected because of the Feiying Armor.

Faced with the threat of Lufa, Xu Tingfei has no choice but to rebuild the Armor team. But looking at the taciturn nine-year-old Xiaotian and the hot-tempered, impulsive eight-year-old Xiaogang in front of him, Xu Tingfei can only feel a headache coming on.

(I know Armor Hero 1 and Armor Hero 2 share the same continuity, but the writers' settings in the two series conflict, and I don't know how to smooth out some of the inconsistencies. So just consider this Xu Tingfei to be from a parallel universe. In his universe, everything is the same as in the original story except Armor Hero 1 doesn't exist. Then, treat the universe he transmigrates to as the main one: it has Armor Hero 1, with Armor Hero 2 following on from it.)