Demonic and divine energy could not exist with each other. Evan knew this well and never allowed them to meet each other in the same body. In his past world, most light mages used spells based on divine energy. In contrast, there were demonologists and dark mages.
There was no way Evan would expect this spell to contain both demonic and divine power. Only demon spells and forbidden dark magic spells contained demonic energy. Evan was sure he could easily sense its presence in another spell, but he didn't notice anything. At the last second of his life, he realized why this had happened.
The demonic and divine energies suppressed each other, causing Evan not to notice their presence in the spell. Moreover, the spell itself was not ordinary at all. Evan assumed that only spells used by members of light organizations would have divine energy. They must have had their own secret techniques and unique spells.