Pro evil won't stop fear and scare IMHO.K. Amaloo said:If one were to cast Magic Circle vs. Chaos, it would prevent enchantment effects - does that include all mind-affecting effects, such as fear from a Scare spell?
Second, the barrier blocks any attempt to possess the warded creature (by a magic jar attack, for example) or to exercise mental control over the creature (including enchantment (charm) effects and enchantment (compulsion) effects that grant the caster ongoing control over the subject, such as dominate person). The protection does not prevent such effects from targeting the protected creature, but it suppresses the effect for the duration of the protection from evil effect. If the protection from evil effect ends before the effect granting mental control does, the would-be controller would then be able to mentally command the controlled creature. Likewise, the barrier keeps out a possessing life force but does not expel one if it is in place before the spell is cast. This second effect works regardless of alignment.
From the 3.0 FAQ (if desired):K. Amaloo said:If one were to cast Magic Circle vs. Chaos, it would prevent enchantment effects - does that include all mind-affecting effects, such as fear from a Scare spell?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.