beyond their A Spirit forms to beat Cherubimon. Kouji uses the spirits of Light, Thunder, Steel, Water, and Darkness to become
MagnaGarurumon and Takuya uses the spirits of Fire, Ice, Wood, Earth, and...
Wind, letting him become KaiserGreymon! Out of the two of them, Izumi's spirits went to Takuya.
My theory on why this happened is this: Takuya and Kouji were able to channel the spirits of those they care for and
those who care the most about them. For Kouji, it was his brother Kouichi. For Takuya, it was not only Tomoki
(who he treats like a brother) but Izumi as well.