Soldier of the Pantheon

Protection from multicolored
Whenever an opponent casts a multicolored spell, you gain 1 life.

Explorer Anthology 2

"I hear the gods' voices in my dreams each night, and I offer bloody trophies on their altars each day."

Theros

Most hybrid spells and permanents, including the ones in the Return to Ravnica block, are multicolored, even if you cast them with one color of mana.

Soldier of the Pantheon can't be enchanted or equipped by multicolored Auras and Equipment, it can't be blocked by multicolored creatures, it can't be targeted by multicolored spells or abilities from multicolored sources, and all damage dealt to it by multicolored sources is prevented.