Question about: Divine Armor

[Tenbian]

Hi there,

Yesterday in a battle, I cast first time Divine Armor on a Unit, because I want to get them better fire-resi for the incoming spell.

Before the cast, the unit had 10% fire resi, after the cast (it shows me 30% on spell description) the unit also had 10% fire resi.

Did I miss something? Also physical, poison and magic-resi didn´t change on the unit.

Regards Tenbian

P.S.: excuse my english pls