Sorcerers Apprentice
Hero
Spirit guardians doesn't separate between enemies and allies, they only accept a "white list" of designated non-targets at the time the spell is cast. Crucially, the caster can only exclude creatures he can see, so if one party member is behind a corner when Spirit Guardians is cast, he will suffer the spell's effects if he enters the radius.
The spell description is pretty explicit about how and when the caster can exclude creatures from the spell.
The spell description is pretty explicit about how and when the caster can exclude creatures from the spell.